/ Dictionary / Index Q quinquennium: Meaning and Definition of Find definitions for: quin•quen•ni•um Pronunciation: (kwin-kwen'ē-um, kwing-), [key] — pl. -quen•ni•ums, -quen•ni•a a period of five years. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: quinquennium (Thesaurus) quinquennial quinquepartite Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language