/ Dictionary / Index S soundproof: Meaning and Definition of Find definitions for: sound•proof Pronunciation: (sound'prf"), [key] — adj. impervious to sound. —v.t. to cause to be soundproof. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: soundproof (Thesaurus) sound pressure sound ranging Related Content Daily Word Quiz: supercilious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language