any of several edible, marine, bivalve mollusks of the family Ostreidae, having an irregularly shaped shell, occurring on the bottom or adhering to rocks or other objects in shallow water.
2.
the oyster-shaped bit of dark meat in the front hollow of the side bone of a fowl.
3.
Slang. a closemouthed or uncommunicative person, especially one who keeps secrets well.
4.
something from which a person may extract or derive advantage: The world is my oyster.
a. any edible marine bivalve mollusc of the genus Ostrea, having a rough irregularly shaped shell and occurring on the sea bed, mostly in coastal waters
b. (as modifier): oyster farm; oyster knife
2.
any of various similar and related molluscs, such as the pearl oyster and the saddle oyster (Anomia ephippium)
3.
the oyster-shaped piece of dark meat in the hollow of the pelvic bone of a fowl
4.
something from which advantage, delight, profit, etc, may be derived: the world is his oyster
5.
informal a very uncommunicative person
—vb
6.
(intr) to dredge for, gather, or raise oysters
[C14 oistre, from Old French uistre, from Latin ostrea, from Greek ostreon; related to Greek osteon bone, ostrakon shell]
1357, from O.Fr. oistre (Fr. huître), from L. ostrea, pl. or fem. of ostreum "oyster," from Gk. ostreon, from PIE *ost- "bone" (see osseous). Related to Gk. ostrakon "hard shell" and to osteon "bone."