Crabs and their close relatives have 10 legs, arranged in five pairs. Some of their legs are used for walking, while others are used for swimming or defense.
Definition of plunge for English Language Learners. : 1  a sudden fall or jump usually from a high place. : 2  a sudden quick fall in amount, value, etc. : 3  the act of suddenly beginning to be in a particular condition or situation.
2. a headlong plunge into water. 3. a steep nose-down descent by an aircraft. Familiarity information: DIVE used as a noun is uncommon. â¢ DIVE (verb). The verb DIVE has 3 senses: 1. drop steeply. 2. plunge into water. 3. swim under water. Familiarity information: DIVE used as a verb is uncommon.