/ Dictionary / Index S solid rocket booster: Meaning and Definition of Find definitions for: sol'id rock'et boost"er Pronunciation: [key] a solid-propellant strap-on rocket used to accelerate a missile or launch vehicle during liftoff. Abbr.: SRB Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. solid propellant solid solution Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language