1. The act of communicating; transmission.
2. 1. The exchange of thoughts, messages, or information, as by speech, signals, writing, or behavior.
   2. Interpersonal rapport.
3. communications (used with a sing. or pl. verb)
   1. The art and technique of using words effectively to impart information or ideas.
   2. The field of study concerned with the transmission of information by various means, such as print or broadcasting.
   3. Any of various professions involved with the transmission of information, such as advertising, broadcasting, or journalism.
4. Something communicated; a message.
5. communications A means of communicating, especially:
   1. A system, such as mail, telephone, or television, for sending and receiving messages.
   2. A network of routes for sending messages and transporting troops and supplies.
6. communications The technology employed in transmitting messages.
7. Biology. The transfer of information from one molecule, cell, or organism to another, as by chemical or electrical signals or by behaviors.
8. Anatomy.
   1. An opening or connecting passage between two structures.
   2. A joining or connecting of solid fibrous structures, such as tendons and nerves.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.