/ Dictionary / Index O oyster crab: Meaning and Definition of Find definitions for: oys'ter crab" Pronunciation: [key] a pea crab, Pinnotheres ostreum, the female of which lives as a commensal within the mantle cavity of oysters. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oystercatcher oyster cracker Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language