/ Dictionary / Index S sound wave: Meaning and Definition of Find definitions for: sound' wave" Pronunciation: [key] — Physics. Physics. a longitudinal wave in an elastic medium, esp. a wave producing an audible sensation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sound truck Sounion Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language