/ Dictionary / Index S speed gear: Meaning and Definition of Find definitions for: speed' gear" Pronunciation: [key] an adjustable gear for driving a machine at various speeds. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. speed freak speed indicator Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language