quinquennial /kwɪŋˈkwɛ.ni.əl/adjective 1noun 3forms 3 adjective1 •Of or related to a five-year period.By a singular coincidence, the great master of the Dorian lyre was born during the celebration of the Pythia, the quinquennial festival of Apollo[…] — 1879 noun3 •A 5th anniversary. •(historical) Synonym of quinquennalia, the festival and religious ritual held in the 5th year of a Roman emperor's reign. •Synonym of quinquennium, a five-year period. formsquinquennials · more quinquennial · most quinquennial
