oys·ter [oysteroysters] BrE [ˈɔɪstə(r)] NAmE [ˈɔɪstər] noun a large flat ↑shellfish. Some types of oyster can be eaten and others produce shiny white ↑jewels called ↑pearls •Oyster beds, on the mudflats, are a form of fish farming. see the world is your oyster at ↑world
Word Origin: Middle English: from Old French oistre, via Latin from Greek ostreon; related to osteon ‘bone’ and ostrakon ‘shell or tile’.