oyster

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several edible bivalve mollusks of the family Ostreidae, especially of the genera Crassostrea and Ostrea, that live chiefly in shallow marine waters and have a rough, irregularly shaped shell.
2. n. Any of various similar or related bivalve mollusks, such as the pearl oyster.
3. n. An edible bit of muscle found in the hollow of the pelvic bone of a fowl.
4. n. A special delicacy.
5. n. Something from which benefits may be extracted.
6. n. Slang A close-mouthed person.
7. v. To gather, dredge for, or raise oysters.

Century Dictionary and Cyclopedia

1. n. An edible bivalve mollusk of the family Ostreidæ, such as Ostrea edulis, the common species of Europe, and O. virginica, that of the Atlantic coast of the United States. The species are very numerous, and are found in all temperate and tropical countries, in salt and brackish water; there are also many fossil species. The shell is very irregular, both inequivalve and inequilateral, with one valve flattened and the other more concavo-convex, both rough outside and nacreous inside. Each valve has one purplish eye or spot, showing where the single adductorial muscle is attached, oysters being thus monomyarian. The gristly button-shaped body in the flesh is this ligament. The soft greenish substance corresponds to a liver. The fluted layers around a part of the body are the gills or breathing-organs. Oysters have sex, and are very prolific. They spawn in north temperate countries in May and June, during which period and for some time afterward they are not so good for food; whence the common saying that oysters are not eatable in those months which have no r in their names. The spawn or fry is called spat or spet. Oysters are now very extensively cultivated, the resulting stock being superior to the natural oyster. Starfishes and some carnivorous gastropods (see borer) are among the great obstacles to success with which oyster-culture has to contend. Oysters feed upon a great many different aquatic organisms of minute size. In confinement they eat corn-meal greedily. See cuts under ciborium, integropalliate, and Ostrea.
2. n. One of many other bivalves of the same order, but of a different family. Thus, the pearl-oyster belongs to the Aviculidæ.
3. n. The oyster-shaped bit of dark meat in the front hollow of the side-bone of a turkey or similar bird.
4. n. Figuratively, some profit or advantage which one may seize and hold.
5. n. Among packers, steamed oysters packed in hermetically sealed cans: a trade-name.
6. To engage in oyster-fishing; take oysters in any way.

Wiktionary

1. n. Any marine bivalve mollusk of the Family Ostreidae, usually found adhering to rocks or other fixed objects in shallow water along the seacoasts, or in brackish water in the mouth of rivers.
2. n. A name popularly given to the delicate morsel of dark meat contained in a small cavity of the bone on each side of the lower part of the back of a fowl.
3. n. A pale beige color tinted with grey or pink, like that of an oyster.
4. n. colloquial, by analogy A person who keeps secrets and private information to him- or herself.
5. adj. Of a pale beige colour tinted with grey or pink, like that of an oyster.
6. v. intransitive To fish for oysters.

GNU Webster's 1913

1. n. (Zoöl.) Any marine bivalve mollusk of the genus Ostrea. They are usually found adhering to rocks or other fixed objects in shallow water along the seacoasts, or in brackish water in the mouth of rivers. The common European oyster (Ostrea edulis), and the American oyster (Ostrea Virginiana), are the most important species.
2. n. A name popularly given to the delicate morsel contained in a small cavity of the bone on each side of the lower part of the back of a fowl.

WordNet 3.0

1. n. a small muscle on each side of the back of a fowl
2. n. edible body of any of numerous oysters
3. n. marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters
4. v. gather oysters, dig oysters