| 1. | 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, esp. one who keeps secrets well. |
| 4. | something from which a person may extract or derive advantage: The world is my oyster. |
| 5. | oyster white. |
| 6. | to dredge for or otherwise take oysters. |
"Why then the world's mine Oyster, which I, with sword will open." [Shakespeare, "The Merry Wives of Windsor," II.ii.2]