/ Dictionary / Index V vicennial: Meaning and Definition of Find definitions for: vi•cen•ni•al Pronunciation: (vī-sen'ē-ul), [key] — adj. of or for 20 years. occurring every 20 years. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: vicennial (Thesaurus) vicenary Vicenza Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language