quinquennĭum

ii, n.

quinquennis

I. a period of five years, five years (class.): CENSORES MAGISTRATVM QVINQVENNIVM HABENTO, Cic. Leg. 3, 3, 7: tria quinquennia, Ov. M. 4, 292: duo, id. ib. 12, 584.
Lewis & Short
A Latin Dictionary, 1879
An open-access project