Oyster (noun)

1. A marine mollusk with a rough irregularly shaped shell, typically found in coastal waters and used as food.
2. Something resembling an oyster in shape or texture, especially something that encloses or contains something precious.

Origin:

Middle english ostere, from old english ōstere, of germanic origin; related to dutch oester and german auster.

Examples:

1. The oyster on the half shell was a delicacy at the seafood restaurant.
2. The pearl was found inside the oyster.
3. Many people enjoy eating oysters raw.
4. The oyster farm is a popular tourist attraction.
5. The oyster was a symbol of wealth and status.