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.
The breaststroke is one of the most popular swimming strokes and involves your lower and upper body moving in sync. The breaststroke is swum in a prone position, with both arms moving synchronously in short, half-circular movements under water. The legs also move synchronously and execute a whip kick.