Crab (noun)

1. A sea creature with a broad carapace, a pair of claws, and stalked eyes, typically living on the sea bed.
2. A crustacean of the infraorder brachyura, typically having five pairs of legs and a hard carapace.

Origin:

Middle english: from old norse krabbi; related to dutch krab and german krebs.

Examples:

1. They caught several crabs on their fishing trip.
2. The restaurant served crab legs as a delicacy.
3. Crabs are found in all oceans.
4. The crab scurried back into its hole.
5. The crab season is open during the summer.