1. the act or process of communicating; fact of being communicated.
2. the imparting or interchange of thoughts, opinions, or information by speech, writing, or signs.
3. something imparted, interchanged, or transmitted.
4. a document or message imparting news, views, information, etc.
5. passage, or an opportunity or means of passage, between places.
a. means of sending messages, orders, etc., including telephone, telegraph, radio, and television.
b. routes and transportation for moving troops and supplies from a base to an area of operations.
7. Biology .
a. activity by one organism that changes or has the potential to change the behavior of other organisms.
b. transfer of information from one cell or molecule to another, as by chemical or electrical signals.