List of acronyms and initialisms: A

This list contains acronyms, initialisms, and pseudo-blends that begin with the letter A.

For the purposes of this list:

• acronym = an abbreviation pronounced as a series of constituent letters, e.g., SARS = severe acute respiratory syndrome
• initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc
• pseudo-blend = an abbreviation whose extra or omitted letters means that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).

(a) = acronym in the example: SARS - (a) Severe acute respiratory syndrome

(i) = initialism in the example: CD - (i) Compact disc

(p) = pseudo-blend in the example: UNIFEM - (p) United Nations Development Fund for Women

(s) = symbol (none of the above, representing and pronounced as something else; for example: MHz - Megahertz)

Add new entries here or in the sub-pages

Please add your own entries, in this page or in the appropriate sub-page. Use a quasi-dictionary order, with lowercase treated the same as uppercase and ignoring non-alphanumeric characters (hyphens and such). This means that only alphanumeric characters have any significance in determining order, and that lowercase letters occupy the same ordering position as uppercase (in tie-breaker cases, list lower case first). For example: Ka appears before KA. (This differs from a strict ASCII ordering.)

(Main list of acronyms and initialisms)

• a - (s) Atto
• A - (s) Ampere
• A - (i) acro (joke acronym)

A0-9

• A2ATD or A²ATD - (i) Anti-Armour Advanced Technology Demonstration
• A2C2 or A²C² - (i) Army Airspace Command and Control
• A4 - many, including a European standard office paper size; see entry

AA

• aa - (s) Afar language (ISO 639-1 code)
• aA - (s) Attoampere
• AA - (i) achieved availability - Alcoholics Anonymous - (s) Armed Forces Americas (postal symbol) - Aruba (FIPS 10-4 territory code) - (i) assembly area - automobile association- avenue of approach
• AAA - (i) administration, authorization, and authentication - American Automobile Association ("Triple-A") - anti-aircraft artillery - Amateur Athletic Association (of England)
• AAAI - (i) American Association for Artificial Intelligence
• AAAS - (i) American Association for the Advancement of Science
• AAAV - (i) advanced amphibious assault vehicle
• AAC - (i) Army Air Corps (British Army)
• AAD - (i) analogue-analogue-digital (CD quality) - Australian Antarctic Division
• AADD - (i) Atlanta Alliance on Developmental Disabilities
• AADT - (i) annual average daily traffic
• AADAC - (a) Alberta Alcohol and Drug Abuse Commission
• AADC - (i) area air defence commander - (i) amino acid decarboxylase - (i) aromatic L-amino acid decarboxylase - (i) Australian Antarctic Data Centre
• AAFC - (i) U.S. Army Air Corps Ferrying Command (1941-1942) - All-America Football Conference (1946–1949)
• AAFES - (i) Army and Air Force Exchange Service
• AAI - (i) applied artificial intelligence
• AAIS - (i) advanced airborne interceptor simulator
• AAM - (i) air-to-air missile
• AAN - (i) American Academy of Nursing
• AANEAS - (a) Anglo-Australian Near-Earth Asteroid Survey
• AAODL - (i) Atmospheric Aerosols and Optics Data Library
• AAP - (i) advanced acquisition plan - Allied administrative publication - American Academy of Pediatrics
• AAPC - (i) Accounting and Auditing Policy Committee
• aar - (s) Afar language (ISO 639-2 code)
• AAR - (i) after-action review - Association of American Railroads
• AARP - (i/s) American Association of Retired Persons (now officially known only by the initials)
• AAS - (i) Advanced Automation System - American Astronomical Society ("double-A-S")
• AASPEM - (i) advanced air-to-air system performance evaluation model
• AAT - (i) Australian Antarctic Territory
• AAV - (i) Amphibious Assault Vehicle
• AAWC - (i) anti-air warfare commander

AB

• ab - (s) Abkhaz language (ISO 639-1 code)
• AB - (i) Able Seaman (rank), Able Seaman (occupation) - (s) Alberta (postal symbol)
• ABA - (i) American Bar Association - American Basketball Association - American Beverage Association - American Bicycle Association - American Birding Association - Australian Broadcasting Authority
• ABB - (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
• ABBA - (a) Agnetha, Benny, Björn, Anni-Frid (Swedish pop group)
• ABC - (i) abstinence, be faithful, condoms - Active Body Control - airway, breathing, circulation (see CPR) - Alcoholic Beverage Commission - alien big cat - always be careful - American Bird Conservancy - American-born Chinese - American Broadcasting Company - anti-lock brake controller - Associated British Corporation - Atanasoff–Berry Computer - Atlantic Baptist College - atomic, biological, chemical (see NBC) - Australian Broadcasting Corporation
• ABCA - (i) American, British and Canadian Armies (originally) - Army Bureau of Current Affairs
• ABCS - (i) (U.S.) Army Battle Command System
• ABET - (a) Accreditation Board for Engineering and Technology
• ABFIST – (i) Advanced Bradley Full Crew Interactive Skills Trainer
• ABGI - (i) Addington-Barker Group International
• ABIN - (a) Agência Brasileira de Inteligência (Brazilian Intelligence Agency)
• abk - (s) Abkhaz language (ISO 639-2 code)
• ABL - (i) American Basketball League
• ABLE - (a) AirBorne Law Enforcement (police air support unit)
• ABM - (i) anti-ballistic missile - Asynchronous Balanced Mode - automated banking machine
• ABMC - (i) American Battle Monuments Commission
• ABN - (i) Australian Business Number (a number issued by the Australian government as registration of a business and used for taxation purposes)
• ABPI - (i) Association of the British Pharmaceutical Industry
• ABRSM - (a) Associated Board of the Royal Schools of Music
• ABS - (i) acrylonitrile butadiene styrene - anti-lock braking system
• ABSA - (a) Amalgamated Banks of South Africa ("ab-sa")
• ABSTRIPS - (p) abstraction-based STRIPS
• ABW - (s) Aruba (ISO 3166 trigram)

AC

• aC - (s) Attocoulomb
• Ac - (s) Actinium
• AC - (i) Adriamycin-Cyclophosphamide (chemotherapy) - Air Conditioning - Aircraftman - Alternating Current - ante Christum (Latin, "before Christ"; see BC) - ante cibum (Latin, "before meals") - (s) Antigua and Barbuda (FIPS 10-4 country code) - (i) Associazione Calcio (Italian, "football (soccer) club") - Altocumulus
• A/C - (i) Air Conditioned/Conditioning - Aircraft
• AC1 - Aircraftman 1st Class
• AC2 - Aircraftman 2nd Class
• ACA - (i) - (i) Airspace Control Authority - Airspace Co-ordination Area - A Current Affair
• ACARS - (a) Aircraft Communications Addressing and Reporting System
• ACAS - (a) Aboriginal Children's Advancement Society - Advisory, Conciliation and Arbitration Service
• ACB - (i) Asociación de Clubes de Baloncesto (Spanish for "Association of Basketball Clubs")
• ACC - (i) U.S. Air Combat Command - Air Component Commander - Altocumulus castellanus - Atlantic Coast Conference - Automatic Climate Control - Area Control Center, Alpine Club of Canada
• ACCA - (i) Automatic Cloud Cover Assessment
• ACCD - American Coalition of Citizens with Disabilities
• ACCAC - (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
• ACCS - (i) Air Communications and Control Squadron
• ACDA - (i) Arms Control & Disarmament Agency
• ACDC - (i) Alternating Current Direct Current, also the name of an Australian rock music band and a term for a bisexual person
• A/Cdre - Air Commodore
• ACDT - (a) Apple Certified Desktop Technician - (a) Australian Central Daylight Time
• ACE - (a) Air Combat Emulator (computer game) - Allied Command Europe - Armored Combat Earthmover - Automatic Computing Engine
• ACES - (a) Auxiliary Campus Enterprises and Services of Alfred State College
• ACES - (a) Aerolineas Centrales de Colombia
• ACF - (i) American Car and Foundry - American Culinary Federation - Administration for Children and Families
• ACHT - (i) Average Call Hold Time
• ACID - (a) Atomicity, Consistency, Isolation, and Durability (in databases)
• ACINT - (p) Acoustic Intelligence
• ACK - (p) Acknowledge (telecommunications; cf. NAK)
• ACL - (i) Access Control List - Anterior Cruciate Ligament
• ACLOS - (i) Automatic CLOS (missile control system)
• ACLS - (i) Alternate Crops and Systems Lab
• ACLU - (i) American Civil Liberties Union, alt. American Communist Lawyers Union by Kent Hovind
• ACM - many, including Association for Computing Machinery; see entry
• ACMC - (i) (U.S.) Assistant Commandant of the Marine Corps
• ACN - (i) Airborne Communications Node - Australian Company Number (number issued by the Australian government as registration of a limited liability company)
• ACO - (i) Airspace Control Order
• ACOBA - (a) Advisory Committee on Business Appointments
• ACOG - (a) American College of Obstetricians and Gynecologists
• ACOM - (p) (U.S.) Atlantic Command
• ACORN - (a) Association of Community Organizations for Reform Now
• ACP - (i) Air Control Point
• ACR - (i) Advanced Concepts and Requirements
• ACRI - (p) African Crisis Initiative
• ACRONYM - (i) Abbreviated Coded Rendition of Name Yielding Meaning
• ACS - (i) Affiliated Computer Services (NYSE ACS) - American Cancer Society - American Chemical Society - Association of Caribbean States
• ACSC - (i) Army Command and Staff College (various nations)
• ACST - (i) Australian Central Standard Time
• ACST - (i) American Cooperative School of Tunis
• act - acting
• ACT - (i) Adaptive Control of Thought (cognitive model) – Australian Capital Territory (postal symbol) – American College Test(ing Program), now known simply by the initials
• ACTD - (i) Advanced Concept Technology Demonstration
• ACTF - (i) Australian Children's Television Foundation - (U.S.) Army Constructive Training Federation
• ACT-R - (i) ACT-Rational (cognitive model)
• ACT-R/PM - (i) ACT-R/Perceptual-Motor (cognitive model)
• ACTU - (i) Australian Council of Trade Unions
• ACU - (a) American Conservative Union
• ACUF - (i) BGN Advisory Committee on Undersea Features
• ACUF - (a) American Conservative Union Foundation
• ACV - (i) Armoured Combat Vehicle

AD

• AD - (i) Air Defence - (s) Andorra (ISO 3166 digram) - (i) Anno Domini (Latin, "In the year of our Lord")
• A/D - (i) Analog/Digital
• ADA - (i) Air Defence Artillery - American Dental Association - Assistant District Attorney - Americans with Disabilities Act (see also the similar but non-acronymic Ada programming language)
• ADA - Another Damn Acronym
• ADAGE - (a) Air Defense Air to Ground Engagement (simulation)
• ADAP - (i) AIDS Drug Assistance Program
• ADAS - (a/i) Asiago-DLR Asteroid Survey
• ADAT - (i) Alesis Digital Audio Tape (recording format)
• ADatP - (p) Automated Data Processing
• ADATS - (i) Agricultural Development and Training Society - Air Defence Anti-Tank System - Australian Defence Air Traffic System
• ADB - (i) Asian Development Bank
• ADC - (i) Aide De Camp - U.S. Air Defense Command (1946-1992) - Apple Display Connector - Program Against Digital Counterfeiting of Currency
• ADCTS - (i) Advanced Distributed Combat Training System
• ADD - (i) Analog Digital Digital (CD quality) - Attention-Deficit Disorder - Administration on Developmental Disabilities
• ADDIE - (i) Analyze Design Develop Implement and Evaluate
• ADDNS - (i) Advanced Deployable Day/Night Simulation
• ADF - (i) Australian Defence Force - African Development Foundation
• ADGB - Air Defence of Great Britain
• ADHD - (i) Attention-Deficit Hyperactivity Disorder
• ADHS - (i) Attention-Deficit Hyperactivity Syndrome
• ADI - (i) Acceptable/Allowable Daily Intake
• ADIZ - (a/i) Air Defence Identification Zone
• ADL - (i) Anti-Defamation League
• ad loc. - (p) ad locum (Latin, "to/at the place")
• ADM - (i) Administrative - (s) - Admiral, and the U.S. Public Health Service Commissioned Corps - Archer Daniels Midland - Assistant Deputy Minister
• ADOA - (a/i) Air Defence Operations Area
• ADP - (i) Adenosine DiPhosphate - Army Doctrine Publication (UK, Canada, Australia) - Automatic/Automated Data Processing
• ADRG - (p) Arc-second Raster Chart (ARC) Digitized Raster Graphics
• ADS - (a/i) Active Denial System - Astrophysics Data System - Attention Deficit Syndrome
• ADSR - (i) Attack, Decay, Sustain, Release (sound envelope specification)
• ADT - (i) Atlantic Daylight Time (UTC-3 hours)
• ADTB - (i) Army Doctrine and Training Bulletin
• adv. - (p) adversus (Latin, "against")
• ADW - (i) Air Defence Warning

AE

• ae - (s) Avestan language (ISO 639-1 code)
• AE - (s) Armed Forces Africa/Canada/Europe/Middle East (postal symbol) - United Arab Emirates (ISO 3166 digram; FIPS 10-4 country code), Artix Entertainment
• AED - (s) United Arab Emirates dirham (ISO 4217 currency code)
• AEDT - (a) Australian Eastern Daylight Time
• AEF - (i) American Expeditionary Force
• AEGIS - (p) Airborne Early warning Ground environment Interface Segment (fake etymology)
• AEI-T - (i) Army Enterprise Infostructure-Transport
• aeq. - (p) aequalis (Latin, "equal")
• AESR - (i) Aeronautical Equipment Service Record
• AEST - (a) Australian Eastern Standard Time
• aet. - (p) aetatis (Latin, "of age", "aged")
• aet - (i) After extra time (Football)
• AEW - (i) Airborne Early Warning - Airborne Electronic Warfare

AF

• af - (s) Afrikaans language (ISO 639-1 code)
• aF - (s) Attofarad
• AF - (s) Afghanistan (FIPS 10-4 country code; ISO 3166 digram) - (i) Air Force
• AFA - (i) U.S. Air Force Academy
• AFAIC - (i) As Far As I'm Concerned
• AFAICT - (i) As Far As I Can Tell
• AFAIK - (i) As Far As I Know
• AFAIR - (i) As Far As I Remember/Recall
• AFATDS - (i) Advanced Field Artillery Tactical Data System
• AFC - (i) American Football Conference - Asian Football Confederation
• AFCEA - (i) Armed Forces Communications and Electronics Association
• AFDB - (i) African Development Bank
• AFES - (i) Automatic Fire Extinguishing System
• AFG - (s) Afghanistan (ISO 3166 trigram)
• AFI - (s) French Territory of the Afars and Issas (ISO 3166 trigram; obsolete since 1977)\ - "Agencia Federal de Investigaciónes" (México)
• AFIS - (a) Automated Fingerprint Identification System - American Forces Information Service
• AFIST - (i) Abrams Full Crew Interactive Skills Trainer
• AFJ - (i) April Fool's Joke
• AFK - (i) Away From Keyboard (Internet chat abbreviation)
• AFL - (i) American Federation of Labor - American Football League - Arena Football League - Australian Football League
• AFL-CIO - (i) American Federation of Labor - Congress of Industrial Organizations
• AFLAC - (a) American Family Life Assurance Company of Columbus
• AFM - (i) Army Field Manual (UK; the U.S. more frequently uses just FM) - Atomic Force Microscope - Aviation Fleet Maintenance
• AFN - (s) Afghani (ISO 4217 currency code)
• AFO - (i) Association of Field Ornithologists
• AFOSR - (i) U.S. Air Force Office of Scientific Research
• AFP - (a) Australian Federal Police
• AFQT - (i) Armed Forces Qualification Test
• afr - (s) Afrikaans language (ISO 639-2 code)
• AFRC - (i) Air Force Reserve Command
• AFRL - (i) Air Force Research Laboratory
• AFROTC - (i) Air Force Reserve Office Training Corps
• AFRRI - (i) (U.S.) Armed Forces Radiobiology Research Institute
• AFRTS - (i) Armed Forces Radio and Television Service
• AFS - (i) Active Front Steering - Air Facility Sub-System - Amniotic Fluid-derived Stem cell
• AFS&A or AFSA - (i) U.S. Air Force Studies and Analysis
• AFSC - (i) U.S. Air Force Staff College (obsolete; replaced with JFSC). - U.S. Air Force Systems Command
• AFSCN - (i) U.S. Air Force Satellite Control Network
• AFSPC - (i) Air Force Space Command
• AFT - American Farmland Trust
• AFV - (i) Armoured Fighting Vehicle
• AFWA - (a) Air Force Weather Agency - Association of Fish and Wildlife Agencies
• AFYA - (i) Anything to Fool Young Andy. Acronym that's real meaning is hidden.

AG

• ag - (s) Attogram
• Ag - (s) Silver (Latin argentum)
• AG - (i) air gunner - Aktiengesellschaft (German, "incorporated") - (s) Algeria (FIPS 10-4 country code) - Antigua and Barbuda (ISO 3166 digram) - Assemblies of God
• AGA - (a/i) AB Gas-accumulator ("ah-gah", Swedish company) - Advanced Graphics Architecture
• AGARD - (a) Advisory Group for Aerospace Research and Development
• AGARDograph - (p) Advanced Guidance for Alliance Research and Development publication
• AGASA - (a) Akeno Giant Air Shower Array (cosmic ray detector)
• AGB - (i) Internal Nintendo initialism (Advanced Game Boy) for Game Boy Advance
• AGC - (i) Apollo Guidance Computer - Automatic Gain Control
• AGC - (i) Adjutant General's Corps (British Army)
• AGDC - (i) Australian Game Developers' Conference
• AGI - (i) Auxiliary Group Intelligence
• AGL - (i) Above Ground Level
• AGM - (i) Annual General Meeting
• AGN - (i) Active Galactic Nucleus
• AGO - (s) Angola (ISO 3166 trigram)
• AGP - (i) Accelerated Graphics Port
• AGRICOLA (a) Agriculture Online Access
• AGS - (i) Alaska Ground Station (LandSat)
• AGTS - (i) Advanced Gunnery Training System
• AGU - (i) American Geophysical Union
• AGW - (i) Autonomous Guided Weapon

AH

• aH - (s) Attohenry
• Ah - (s) Ampere-hour
• AH - (i) Attack Helicopter
• AHA - (i) American Heart Association
• AHCPR - (i) Agency for Health Care Policy and Research (obsolete; replaced with AHRQ)
• AHEC - (i) Australian Health Ethics Committee
• AHPCRC - (i) Army High Performance Computing Research Center
• AHQ - Air Headquarters
• AHRQ - (i) Agency for Healthcare Research and Quality
• AHS - (i) American Housing Survey

AI

• AI - (i) Air Interdiction - (s) Anguilla (ISO 3166 digram) - (i) Amnesty International - Artificial Insemination - Artificial Intelligence
• AIA - (i) Aerospace Industries Association - American Institute of Architects - (s) Anguilla (ISO 3166 trigram)
• AIAA - (i) American Institute of Aeronautics and Astronautics
• AIC - (i) African Independent Church - (i) Animal Identification Coordinator
• AICD - (i) Australian Institute of Company Directors
• AICMFP - (i) And I Claim My Five Pounds
• AID - (i) U.S. Agency for International Development
• AIDS - (a) Acquired Immune Deficiency Syndrome
• AIM - many, including AOL Instant Messenger, Australian Institute of Management; see entry
• AIMP - (i) Aurora Incremental Modernization Project
• AIPAC - (i) American Israel Public Affairs Committee
• AIR - (i) Aircraft Inventory Record
• AIRFA - (a) American Indian Religious Freedom Act
• AIRS - (a/i) Aerometric Information Retrieval System (obsolete; replaced with AFS)
• AIS - (i) Automatic Identification System
• AISB - (i) (British Society for the Study of) Artificial Intelligence and the Simulation of Behaviour

AJ

• aJ - (s) Attojoule
• AJ - (s) Azerbaijan (FIPS 10-4 country code)
• Ajax - (a) Asynchronous JavaScript And XML
• AJD - (i) Astronomical Julian Day
• AJP - (i) Allied Joint Publication

AK

• ak - (s) Akan languages (ISO 639-1 code)
• aK - (s) Attokelvin
• AK - (s) Alaska (postal symbol)
• aka - (s) Akan languages (ISO 639-2 code)
• a.k.a. - (i) Also known as (i.e.: alias)
• AKDT - (p) Alaska Standard Daylight Saving Time (UTC-8 hours)
• AKST - (p) Alaska Standard Time (UTC-9 hours)
• AKA - Above knee amputation (orthopaedic usage)

AL

• aL - (s) Attolitre
• Al - (s) Aluminium
• AL - (s) Alabama (postal symbol) - Albania (FIPS 10-4 country code; ISO 3166 digram) - (i) Anno Lucis (Latin, "Year of Light", in Masonic tradition, most often seen on plaques bearing the founding dates of buildings, in years AD and years AL)
• ALA - (s) Åland Islands (ISO 3166 trigram)
• ALAP - (a) As Long/Late As Possible
• ALARM - (a) Air-Launched Anti-Radar Missile
• ALB - (s) Albania (ISO 3166 trigram)
• ALD - (i) Accounting Line Designator (nuclear weapon targeting)
• ALERT - (a) Advanced Linked Extended Reconnaissance and Targeting - Attack and Launch Early Reporting to Theatre
• ALF - (a) Africa Leadership Forum - Alien Life Form - Animal Liberation Front
• ALGOL - (p) ALGOrithmic Language
• ALL - (s) Albanian lek (ISO 4217 currency code)
• ALOA - (i) Associated Locksmiths of America, Inc.
• ALOC - (a) Air Lines Of Communication
• ALOC - (a) Average Length of Calls
• ALPA - (a) Air Line Pilots Association
• ALS - (i) Amyotrophic Lateral Sclerosis - Automatic Landing System
• ALSHS - (a) Abraham Low Self-Help Systems
• ALSP - (i) Aggregate Level Simulation Protocol
• ALTE - (a) Association of Language Testers in Europe
• ALTACS - (p) Automated decision Logic Tactical Air Combat Simulation

AM

• am - (s) Amharic language (ISO 639-1 code) - Attometre
• Am - (s) Americium
• AM - many, including Amplitude Modulation and Ante Meridiem; see entry - (s) Armenia (FIPS 10-4 country code; ISO 3166 digram)
• AM1 - Airman 1st class
• AMA - (i) American Medical Association - (i) Australian Medical Association
• AMAPS - (a) Aircraft, Missile, Avionics Performance Simulation
• AMC – (i) Adaptive modulation and coding (digital communications) - U.S. Air Mobility Command - American Motors Corporation - U.S. Army Materiel Command - American Movie Classics (TV network; now known simply by the initials)
• AMCB - (i) U.S. Army/Marine Corps Board
• AMD - (i) Advanced Micro Devices - Age-related Macular Degeneration - (s) Armenian dram (ISO 4217 currency code)
• AMF - (i) Afghan Military Force(s)
• AMFOM - (i) Advanced Missile Fly Out Model ("am-fomm")
• AMFR - (i) Age-specific Marital Fertility Rate - Amplitude Modulation Following Response
• AMFRS - (i) Advanced Multi-Function Radio Frequency System - Automatic Multisensor Feature-based Recognition System
• amh - (s) Amharic language (ISO 639-2 code)
• AML - (i) Acute Myeloid Leukaemia
• AMLCD - (i) Active Matrix Liquid Crystal Display
• AMO - (i) Atlantic Multidecadal Oscillation
• AMOS - (a) Advanced MOrtar System - Air Force Maui Optical and Supercomputing observatory
• AMP - (i) Adenosine MonoPhosphate - Automated Mission Planner
• AMRAAM - (a) Advanced Medium-Range Air-to-Air Missile
• AMRDEC - (i) U.S. Aviation & Missile Research, Development, & Engineering Center
• AMS - (i) Agriculture Marketing Service - American Mathematical Society
• AMSAA - (i/a) U.S. Army Materiel Systems Analysis Activity
• AMSO - (i/a) U.S. Army Model and Simulation Office
• AMSU - (i) Association for Managers in Students' Unions - Aviation Matériel Screening Unit
• AMTE - (i) UK Admiralty Marine Technology Establishment (1977–1984)

AN

• an - (s) Aragonese language (ISO 639-1 code)
• aN - (s) Attonewton
• AN - (s) Andorra (FIPS 10-4 country code) - Netherland Antilles (ISO 3166 digram)
• ANA - (i) Administration for Native Americans - Afghan National Army - All Nippon Airways - Anti-Nuclear Anti-body - (a) Australian National Airways - (a) Australian Natives Association
• ANC - (i) African National Congress
• AND - (s) Andorra (ISO 3166 trigram)
• ANG - (i) Air National Guard - (s) Netherlands Antillian guilder (ISO 4217 currency code)
• ANGLiCo - (p) Air/Naval Gunfire Liaison Company
• ANL - (i) Argonne National Laboratory
• ANM - (i) Acoustic Noise Monitor
• ANOVA - (p) ANalysis Of VAriance
• ANS - (i) Applied and Natural Sciences
• ANSI - (a) American National Standards Institute
• ANTM - America's Next Top Model
• ANT - (s) Netherland Antilles (ISO 3166 trigram)
• ANZ - (s) Australia and New Zealand Banking Group
• ANZAC - (a) Australian and New Zealand Army Corps

AO

• AO - (s) Angola (FIPS 10-4 country code; ISO 3166 digram) - (i) Approach Officer (submarine) - Area of Operations
• AOA - (i) Air Officer in charge of Administration - Argonne National Laboratory - (s) Angolan kwanza (ISO 4217 currency code) - (i) Award Of Arms (heraldry)
• AOC - (i) Air Operations Centre - Air Officer Commanding
• AOC in C - Air Officer Commanding in Chief
• AOD - (i) Adrenalin O.D. (punk rock band)
• AOI - (i) Angle Of Incidence (i) Arab Organization for Industrialization
• AOL - (i) America OnLine
• AOR - (i) Area Of Responsibility
• AOSTH - Adventures of Sonic the Hedgehog
• AOU - (i) American Ornithologists' Union

AP

• AP - (i) Advanced Placement - Air Publication - (s) Armed Forces Pacific (postal symbol) - (i) Associated Press - Auto Pilot
• APA -(i) American Psychiatric Association
• APB - (i) All Points Bulletin (police jargon)
• APC - (i) Armoured Personnel Carrier - Armour Piercing Capped (ammunition)
• APEC - (a) Asia Pacific Economic Cooperation
• APCNR - (i) Armour-Piercing, Composite Non-Rigid (ammunition)
• APCR - (i) Armour-Piercing, Composite Rigid (ammunition)
• APDS - (i) Armour-Piercing, Discarding-Sabot (ammunition)
• APEDS - (a) AMSAA Performance Estimates Data System
• APFSDS - (i) Armour-Piercing, Fin-Stabilised, Discarding Sabot (ammunition)
• APHA - (i) American Public Health Association
• APHE - (i) Armour-Piercing, High Explosive (ammunition)
• APHIS - (a) Animal and Plant Health Inspection Service
• API - (i) Application Programming Interface
• APL - (i) A Programming Language - Acute Promyeloid Leukaemia - Anti-Personnel Landmine - Applied Physics Laboratory (Johns Hopkins University)
• APM - (i) Advanced Power Management
• APOD - (i) Aerial Port (Airport) Of Debarkation
• APOE - (i) Aerial Port (Airport) Of Embarkation
• APOLLO - (a) Apache Point Observatory Lunar Laser-ranging Operation
• APP - (i) Allied Procedural Publication
• APR - (i) Annual Percentage Rate
• APS - (i) American Physical Society - Antiphospholipid Antibody Syndrome

AQ

• AQ - (s) American Samoa (FIPS 10-4 territory code) - Antarctica (ISO 3166 digram) - AdventureQuest

AR

• ar - (s) Arabic language (ISO 639-1 code)
• Ar - (s) Argon
• AR - (s) Argentina (FIPS 10-4 country code; ISO 3166 digram) - Arkansas (postal symbol) - Armour
• ara^{[disambiguation needed]} - (s) Arabic language (ISO 639-2 code)
• ARAG - (a) Advanced Research and Assessment Group
• ARB - (i) Administrative Review Board
• ARBA - (a/i) Army Review Boards Agency
• ARC - (i) Arc-second Raster Chart - Appalachian Regional Commission
• ARCA – (a) Automobile Racing Club of America
• ARCENT - (p) United States Army Central Command
• ARDA - (a) Advanced Research and Development Activity (became DTO 2006)
• ARE - (i) UK Admiralty Research Establishment (–1991) - (s) United Arab Emirates (ISO 3166 trigram)
• ARF - (i) ASEAN Regional Forum
• arg - (s) Aragonese language (ISO 639-2 code)
• ARG - (s) Argentina (ISO 3166 trigram)
• ARH - (s) Armed Reconnaissance Helicopter
• ARI - (i) Acute Respiratory Infection - U.S. Army Research Institute for the Behavioral and Social Sciences
• ARL - (i) UK Admiralty Research Laboratory (1921–1977) - U.S. Army Research Laboratory - UIUC Aviation Research Laboratory
• ARM - (a) Anti-Radiation Missile - Adjustable Rate Mortgage - (s) Armenia (ISO 3166 trigram)
• ARNet - (p) Acquisition Reform Network
• ARP - (i) Address Resolution Protocol - Applied Research Programme
• ARPA - (a) Advanced Research Projects Agency
• ARRC - (i) ACE Rapid Reaction Corps
• ARRF - (i) Allied Rapid Reaction Force
• ARS - (i) Agricultural Research Service - (s) Argentine peso (ISO 4217 currency code)
• ARSC - (i) Arctic Region Supercomputing Center
• ARSPACE - (p) U.S. Army Space Command
• ART - (a) Adaptive Resonance Theory - Anti-Retroviral Therapy
• ARTCC - (i) Air Route Traffic Control Center
• ARWG - (i) Army Research Working Group ("are-wig")

AS

• as - (i) Adult swim - (s) Assamese language (ISO 639-1 code) - Attosecond
• aS - (s) Attosiemens
• As - (s) Arsenic
• AS - (s) American Samoa (postal symbol; ISO 3166 digram) - Australia (FIPS 10-4 country code)
• AS - (i) ActionScript
• A/S - (i) Anti-submarine
• A&S - (i) Armament & Standardisation
• ASA - (i) AcetylSalicylic Acid - American Standards Association - Army Security Agency - Atlantic Southeast Airlines
• ASAP - (a) As Soon As Possible
• ASARS - (a) Advanced Synthetic Aperture Radar System - Airborne Search and Rescue System
• ASB - (i) Associated Student Body - Alternative Service Book (Church of England)
• asbl - (i) association sans but lucratif (French "Non-profit organisation")
• ASBO - (a) Anti-Social Behaviour Order
• ASCAP - (a) American Society of Composers, Authors, and Publishers
• ASCC - (i) Army Service Component Commander - Automatic Sequence Controlled Calculator - Air Standardization Coordinating Committee
• ASCIET - (i) All Services Combat Identification Evaluation Team
• ASCII - (a) American Standard Code for Information Interchange
• ASC+T - (i) Anti Slip Control + Traction
• ASD - (i) (U.S.) Assistant Secretary of Defense - autism spectrum disorder
• ASD(C3I) - (i) (U.S.) (Command, Control, Communications, & Intelligence)
• ASD(FMP) - (i) (U.S.) Assistant Secretary of Defense (Force Management Policy)
• ASD(HA) - (i) (U.S.) Assistant Secretary of Defense (Health Affairs)
• ASD(ISA) - (i) (U.S.) Assistant Secretary of Defense (International Security Affairs)
• ASD(ISP) - (i) (U.S.) Assistant Secretary of Defense (International Security Policy)
• ASD(LA) - (i) (U.S.) Assistant Secretary of Defense (Legislative Affairs)
• ASD(PA) - (i) (U.S.) Assistant Secretary of Defense (Public Affairs)
• ASD(RA) - (i) (U.S.) Assistant Secretary of Defense (Reserve Affairs)
• ASD(SO&HA) - (i) (U.S.) Assistant Secretary of Defense (Special Operations & Humanitarian Assistance)
• ASD(SO/LIC) - (i) (U.S.) (Special Operations & Low-Intensity Conflict)
• ASD(S&R) - (i) (U.S.) Assistant Secretary of Defense (Strategy & Requirements))
• ASD(S&TR) - (i) (U.S.) Assistant Secretary of Defense (Strategy & Threat Reduction)
• ASDIC - (a) Allied Submarine Detection Investigation Committee (Sonar)
• ASEAN - (a) Association of South East Asian Nations
• ASFAR - (a) Americans for a Society Free of Age Restrictions
• ASG - (i) Area Support Group
• ASIC - (a) Australian Securities and Investments Commission - (a) Aviation Security Identification Card
• ASICS - (a) Anima sana in corpore sano (Latin, "A sound mind in a sound body") (athletic shoe manufacturer)
• ASIO - (a) Australian Security Intelligence Organisation - (a) Audio stream input output
• ASIP - (i) Advanced System Improvement Program - Army Stationing and Installation Plan - Application-specific instruction-set processor
• ASL - (i) Above Sea Level - American Sign Language (also known as Ameslan) - "Age, Sex, Location?" (Internet slang)
• asm - (s) Assamese language (ISO 639-2 code)
• ASM - (i) Air-to-Surface Missile - (s) American Samoa (ISO 3166 trigram) - (i) American Society for Metals - (i) American Society for Microbiology
• ASMB - (i) American Society for Matrix Biology
• ASMB - (i) Adult Swim Message Board
• ASME - (i) American Society of Mechanical Engineers
• ASME - (i) American Society of Magazine Editors
• ASMP - (i) Air-Sol Moyenne Portée missile (French "Medium-range air to surface") - (p) Asymmetric multiprocessing
• ASN - (i) Associate of Science in Nursing
• ASOC - (a/i) Air Sovereignty Operations Centre - Air Support Operations Centre - Airport Security and Operations Centre - Antarctic and Southern Ocean Coalition - Atlanta Symphony Orchestra Chorus - Australian Standard Offence Classification
• ASP - (i) Active Server Pages - American Society of Primatologists - Ammunition Supply Point - Application Service Provider (cf internet service provider) - Astronomical Society of the Pacific - Association of Surfing Professionals
• ASPI - (i) Australian Strategic Policy Institute
• ASR - (i) Anti Slip Regulation
• ASRAAM - (a) Advanced Short-Range Air-to-Air Missile
• ASSC - (i) Association for the Scientific Study of Consciousness
• Ass Paym - Assistant Paymaster
• AST - (i) Atlantic Standard Time (UTC-4 hours)
• ASTIA - (a) Armed Services Technical Information Agency
• ASTM - (i) American Society for Testing and Materials
• ASTREA - (a) Aerial Support To Regional Enforcement Agencies (sheriff's air support unit)
• ASUW - (p) AntiSUrface Warfare
• ASVEL – (a) Association Sportive Villeurbanne Éveil Lyonnais (Association Sportive is French for "Sporting Association"; the club was founded through the merger of AS Villeurbanne and Éveil Lyonnais)
• ASW - (i) AntiSubmarine Warfare
• ASWORG - (i) (U.S.) AntiSubmarine Warfare Operations Research Group
• ASX - (p) Advanced Stream Redirector - Australian Securities Exchange

AT

• aT - (s) Attotesla
• At - (s) Astatine
• AT - (i) Anti-Tank - (s) Ashmore and Cartier Islands (FIPS 10-4 territory code) - Austria (ISO 3166 digram) - (i) Advanced Technology (IBM Personal Computer/AT)
• ATA - (i) Advanced Technology Attachment (IBM Personal Computer) - Afghan Transitional Authority - Allen Telescope Array - (s) Antarctica (ISO 3166 trigram)
• ATAC - (a) Air Transportable Acoustic Communications
• ATACMS - (p) Army TACtical Missile System
• ATAPI - (a) Advanced Technology Attachment Packet Interface
• ATAS - (a) Air-To-Air Stinger (missile)
• ATAT - (a) Aiken Tactical Airsoft Team / Star Wars vehicle
• ATB - (i) Active Time Battle - (s) British Antarctic Territory (ISO 3166 trigram; merged with AQ in 1979)
• ATC - (i) Air Traffic Control - Air Training Corps - U.S. Air Transport Command (1942-1948)
• ATCCIS - (i) Army Tactical Command and Control Information System
• ATESS - (i) Aerospace and Telecommunications Engineering Support Squadron
• ATF - (s) French Southern Territories (ISO 3166 trigram) - (i) Bureau of Alcohol, Tobacco, and Firearms
• ATFU - (a) Ate The Fuck Up - related to FUBAR
• ATG - (s) Antigua and Barbuda (ISO 3166 trigram)
• ATGM - (i) Anti-Tank Guided Missile
• ATGW - (i) Anti-Tank Guided Weapon
• ATI - (i) Allied Telesyn International, Inc.
• ATK - (p) Attack
• ATL - (p) Atlanta,Georgia, the largest city and capital of Georgia
• ATLAS - (a) All-Terrain Lifter Army System - (p) Assessment Tool for LAnd Systems
• ATM - (i) Automated Teller Machine - Asynchronous Transfer Mode - At The Moment
• ATN - (s) Dronning Maud Land (ISO 3166 trigram; merged with AQ in 1983)
• ATO - (i) Air Tasking Order - Australian Taxation Office
• ATP - (i) Adenosine TriPhosphate - Allied Tactical Publication - Ammunition Transfer Point
• ATSD - (p) (U.S.) Assistant to the Secretary of Defense
• ATSDR - (i) Agency for Toxic Substances and Disease Registry
• AT&T - (i) American Telephone and Telegraph (U.S. company, also known as "Ma Bell")
• ATV - (i) All-Terrain Vehicle
• ATWA - (a) Air, Trees, Water, Animals

AU

• Au - (s) Gold
• AU - (i) African Union (was OAU before 2000) - American University - (s) Astronomical Unit - Australia (ISO 3166 digram) - Austria (FIPS 10-4 country code)
• AUC - (i) Ab Urbe Condita / Anno Urbis Conditae (Latin "from the founding of the city" / "in the year since the founding of the city") (of Rome) - Area Under the Curve (concentration time curve; medicine)
• AUD - (s) Australian dollar (ISO 4217 currency code)
• AUS - (s) Australia (ISO 3166 trigram)
• AUSCANZUKUS - (p) Australia, Canada, New Zealand, United Kingdom, United States (security designation)
• AUT - (s) Austria (ISO 3166 trigram)
• AUTL - (i) Army Universal Task List

AV

• av - (s) Avar language (ISO 639-1 code)
• aV - (s) Attovolt
• AV - (s) Anguilla (FIPS 10-4 territory code) - (i) Audio-Visual - (s) Aviation
• ava - (s) Avar language (ISO 639-2 code)
• AVB - (i) Audio Video Bridging
• AVCATT-A - (p) (U.S. Army's) Aviation Combed Arms Tactical Trainer-Aviation [Reconfigurable Manned Simulator]
• AVDLR - (p) Aviation Depot Level Repair
• ave - (s) Avestan language (ISO 639-2 code)
• AVGP - (i) Armoured Vehicle, General Purpose
• AVI - (i) Audio Video Icon
• AVIM - (p) Aviation Intermediate Maintenance
• AVLB - (i) Armoured Vehicle Launched Body
• AVM - Air Vice-Marshal
• AVO - (i) Apprehended Violence Order
• AVP - (a) Arubaanse Volkspartij
• AVP - (i) Association of Volleyball Professionals
• AVRE - (i) Armoured Vehicle Royal Engineers
• AVTB - (i) Armoured Vehicle Test Bed - (p) Aviation Test Bed
• AVUM - (p) Aviation Unit Maintenanc

AW

• aW - (s) Attowatt
• AW - (s) Aruba (ISO 3166 digram)
• AWA - (i) American Wrestling Association
• AWACS - (a) Airborne Warning And Control System
• AWC - (i) Air Warfare Centre
• AWD - many, including All Wheel Drive; see entry
• AWE - (i/a) Advanced Warfighting Experiment
• AWG - (s) Aruban guilder (ISO 4217 currency code)
• AWOL - (a) Absent Without Official Leave / Absent WithOut Leave (military jargon)
• AWP - (p) Awaiting Parts (SM&R code)
• AWSIM - (p) Air Warfare SIMulation
• AWST - (a) Australian Western Standard Time
• AWW - (i) Above Water Warfare

AX

• AX - (s) Åland Islands (ISO 3166 digram)
• AXP - (p) Ambulance eXchange Point

AY

• ay - (s) Aymara language (ISO 639-1 code)
• AY - (s) Antarctica (FIPS 10-4 territory code)
• AYBABTU - (i) All Your Base Are Belong To Us
• aym - (s) Aymara language (ISO 639-2 code)
• AYU - (i) As Yet Unknown

AZ

• az - (s) Azerbaijani language (ISO 639-1 code)
• AZ - (s) Arizona (postal symbol) - Azerbaijan (ISO 3166 digram) - (i) Alkmaar Zaanstreek (Dutch football club)
• aze - (s) Azerbaijani language (ISO 639-2 code)
• AZE - (s) Azerbaijan (ISO 3166 trigram)
• AZN - (s) Azerbaijanian manat (ISO 4217 currency code)
• AZUR - (p) Actions en zone urbaine (French, Urban Operations)