FUNC’TION(fŭnk shŭn), n, [L. functio, fr fungi to perform, execute, akin to Skr. bhuj to enjoy, have the use of: cf. F. fontcion. Cf. DEFUNCT.]

The act of executing or performing any duty, office, or calling; performance. “In the function of his public calling.” Swift.

2. (Math.) A quantity so connected with another quantity, that if any alteration be made to the latter there will be a consequent alteration in the former.