Pronunciation: (fungk'shun),[key] —n. 1. the kind of action or activity proper to a person, thing, or institution; the purpose for which something is designed or exists; role.
2. any ceremonious public or social gathering or occasion.
3. a factor related to or dependent upon other factors: Price is a function of supply and demand. 4. Math. a. Also calledcorrespondence,map,mapping,transformation. a relation between two sets in which one element of the second set is assigned to each element of the first set, as the expression y = x2; operator.
b. Also calledmultiple-value function. a relation between two sets in which two or more elements of the second set are assigned to each element of the first set, as y2 = x2, which assigns to every x the two values y = +x and y = -x. c. a set of ordered pairs in which none of the first elements of the pairs appears twice.
5. Geom. a. a formula expressing a relation between the angles of a triangle and its sides, as sine or cosine.
b. See hyperbolic function. 6. Gram. a. the grammatical role a linguistic form has or the position it occupies in a particular construction.
b. the grammatical roles or the positions of a linguistic form or form class collectively.
7. Sociol.the contribution made by a sociocultural phenomenon to an ongoing social system.
—v.i. 1. to perform a specified action or activity; work; operate: The computer isn't functioning now. He rarely functions before noon. 2. to have or exercise a function; serve: In earlier English the present tense often functioned as a future. This orange crate can function as a chair.