/ Dictionary / Index T triplane: Meaning and Definition of Find definitions for: tri•plane Pronunciation: (trī'plān"), [key] an airplane with three supporting wings, one above another: a design used mainly in the early history of the airplane. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Tripitaka triple Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language