/ Dictionary / Index O octennial: Meaning and Definition of Find definitions for: oc•ten•ni•al Pronunciation: (ok-ten'ē-ul), [key] — adj. occurring every eight years. of or for eight years. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. octavus* octet Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language