Lewis Short
perfunctĭo (noun F) : perfungor
* A performing, discharging of an office (class.): honorum,Cic. de Or. 3, 2, 7: laborum, an undergoing, enduring (along with perpessio dolorum), id. Fin. 1, 15, 49.—Of things: annua fertur ei totius spatii esse perfunctio, Ambros. Hexaëm. 4, 5, 24.
Charlton T. Lewis, Charles Short, A Latin Dictionary