n. 1 any of various bivalve molluscs of the family Ostreidae or Aviculidae, esp. an edible kind, Ostrea edulus, of European waters. 2 an oyster-shaped morsel of meat in a fowl's back. 3 something regarded as containing all that one desires (the world is my oyster). 4 (in full oyster-white) a white colour with a grey tinge. oyster-bank (or -bed) a part of the sea-bottom where oysters breed or are bred. oyster-catcher any usu. coastal wading bird of the genus Haematopus, with a strong orange-coloured bill, feeding on shellfish. oyster-farm an area of the seabed used for breeding oysters. oyster-plant 1 = SALSIFY. 2 a blue-flowered plant, Mertensia maritima, growing on beaches.
[ ME & OF oistre f. L ostrea, ostreum f. Gk ostreon ]