/ Dictionary / Index T tireless: Meaning and Definition of Find definitions for: tire•less Pronunciation: (tīr'lis), [key] — adj. untiring; indefatigable: a tireless worker. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tireless (Thesaurus) tire iron Tiresias Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language