/ Dictionary / Index A ark shell: Meaning and Definition of Find definitions for: ark' shell" Pronunciation: [key] any marine bivalve of the family Arcidae, esp. of the genus Arca, characterized by a heavy shell with a toothed hinge and a deep, boatlike inner surface. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. arkose arkwright Related Content Daily Word Quiz: sumptuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language