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.
verb (used without object), dived or dove, dived, diving. 1. to plunge into water, especially headfirst. 2. to go below the surface of the water, as a submarine. 3. to plunge, fall, or descend through the air, into the earth, etc.: The acrobats dived into nets. Aeronautics. (of an airplane) to descend rapidly. to penetrate suddenly into something, as with the hand: to dive into one's purse. to dart: to dive into a doorway.