/ Dictionary / Index T triannual: Meaning and Definition of Find definitions for: tri•an•nu•al Pronunciation: (trī-an'y-ul), [key] — adj. done, occurring, issued, etc., three times a year. triennial. —n. a triannual publication, contest, etc. triennial. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Triangulum Australe Trianta Related Content Daily Word Quiz: abdicate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language