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.
Plunge Grinding. Definition. Also called Infeed Grinding, a process of machining cylindrical parts in which the grinding wheel moves radially toward the work and does not leave a spiral groove pattern, which could cause leakage in a seal surface; the grinder is thrusted, fed, or plunged straight into the part.