/ Dictionary / Index D dirt bike: Meaning and Definition of Find definitions for: dirt' bike". Pronunciation: [key] See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. dirt dirt-cheap Related Content Daily Word Quiz: vernacular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language