Pi

Look up pi or PI in Wiktionary, the free dictionary.

Pi, or π, is the mathematical constant equal to a circle's circumference divided by its diameter.

Pi or PI may also refer to:

Letter Pi (π)

Lower-case π

• Pi (letter), the Greek letter
• Lowercase π:
  • (pi function), the prime-counting function
  • π_n(X) the n-th homotopy group of X.
  • Pi bond
  • Osmotic pressure
  • A song from the Kate Bush album Aerial
  • Shorthand for pion
  • A men's fragrance from Givenchy
  • The symbol for political life used in Boethius' Consolation of Philosophy
  • Pi-calculus, a process calculus.
• Uppercase Π:
  • The product symbol
  • (Pi function), the Gamma function when offset to coincide with the factorial
    • , the reciprocal of the Pi reciprocal.
  • , a set in the Arithmetical hierarchy.
  • , a set in the Analytical hierarchy.

Pi as a word

Look up 皮 in Wiktionary, the free dictionary.

• Pi (instrument)
• Pi (.hack), a fictional character from the multimedia franchise .hack//G.U.
• Pi Magazine
• Pi Recordings, a record label
• "Pi", a song from the Hard 'n Phirm album Horses and Grasses, which is 3:14 in length
• Pi, a member of Team Robo in Sega Soccer Slam
• Pi, a fictional character in the novel Life of Pi
• Pi County, county in Sichuan, China
• Pi (film), a 1998 film directed by Darren Aronofsky
• Pi Studios, a video game developer based in Houston, Texas
• 皮 (hanyu pinyin : Pí), a Chinese character meaning skin, bark

PI as an abbreviation

Science

• Primary immunodeficiency
• An inorganic phosphate group (as P_i)
• The isoelectric point (as pI)
• Phosphatidylinositol
• Propidium iodide
• Polyimide
• Potential instability
• Protease inhibitor
• Pistillata a gene that influences the development of flowers in the ABC Model of Flower Development
• Prediction interval in statistics

Companies and organizations

• Parents for Inclusion
• Perimeter Institute for Theoretical Physics
• Privacy International
• Pasteur Institute
• Sun Air (Fiji) (IATA airline code: PI)

Professional occupations

• Photographic interpreter, an aerospace and strategic reconnaissance term
• In legal shorthand, it refers to a plaintiff
• Personal injury attorney
• Principal investigator
• Private investigator

Computing

• Page impressions, an online advertising term
• Pebi, a Binary prefix
• Programmed instruction
• Provider Independent Address Space

Other

• Pass interference in American football
• Parameter indicator, in ISO standards
• People's Initiative
• Personal information
• Profitability index
• Personal injury
• The Philippines (from "Philippine Islands")
• PI controller, a concept in automation and control engineering
• Poison Idea, American hardcore punk band
• Public intoxication
• Seattle Post-Intelligencer
• Philippine Idol
• Primitive Instinct
• Proforma invoice
• Plasticity Index
• Prison Industry, as often coined on the Fox hit series Prison Break
• Marine Corps Recruit Depot Parris Island

See also

• P
• Pie (disambiguation)

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