/ Dictionary / Index T triathlete: Meaning and Definition of Find definitions for: tri•ath•lete Pronunciation: (trī-ath'lēt), [key] — n. a competitor in a triathlon. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Triassic triathlon Related Content Daily Word Quiz: wizened Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language