/ Dictionary / Index S solid propellant: Meaning and Definition of Find definitions for: sol'id propel'lant Pronunciation: [key] a rocket propellant in solid form, usually containing a mixture or combination of fuel and oxidizer. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. solid of revolution solid rocket booster 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