/ Dictionary / Index E expansion wave: Meaning and Definition of Find definitions for: expan'sion wave" Pronunciation: [key] a shock wave that expands the medium through which it is transmitted. Cf. compression wave. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. expansion team expansive Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language