/ Dictionary / Index R run-flat: Meaning and Definition of Find definitions for: run-flat Pronunciation: (run'flat"), [key] — adj. (of an automobile tire) constructed so as not to deflate completely after a puncture so that a motorist can still drive the vehicle for some distance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rune-stone rung Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language