1530s, "one's proper work or purpose; power of acting in a specific proper way," from Middle French fonction (16c.) and directly from Latin functionem (nominative functio) "a performance, an execution," noun of action from funct-, past participle stem of fungi "perform, execute, discharge," from PIE root *bheug- (2) "to use, enjoy" (see brook, v.). Meaning "official ceremony" is from 1630s, originally in church use. Use in mathematics probably was begun by Leibnitz (1692). In reference to computer operations, 1947.

1844, "perform a function" (intransitive), from function, n.. Related: Functioned; functioning.