/ Dictionary / Index D date mussel: Meaning and Definition of Find definitions for: date' mus"sel Pronunciation: [key] any brown, date-sized marine mussel, genus Lithophaga, that bores into rock or coral. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. date line date of record Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language