/ Dictionary / Index D delta wave: Meaning and Definition of Find definitions for: del'ta wave" Pronunciation: [key] — Physiol. Physiol. any of the slow brain waves constituting delta rhythm. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. delta virus delta wing Related Content Daily Word Quiz: jaundice Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language