I. (ˈ)kwin|kwenēəl, -enyəl adjective
Etymology: Middle English quinqueniale, from Middle French quinquennial, from Latin quinquennium period of five years (from quinque- + -ennium, from annus year) + Middle French -al — more at annual
1. : occurring once in five years
quinquennial enumeration
: occurring at the end of every five years
2. : lasting five years
a quinquennial grant
has a place in the quinquennial and annual economic plans of the country — J.P.M.Somerville
II. noun
( -s )
: a quinquennial term or office