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.
An endless pool, sometimes referred to as a treadmill for swimmers, is a small swimming pool designed to provide aquatic exercise for those who do not own a large enough space for a full-size pool. From the moment it was invented in the 1980s, endless pools became popular in the market as an exercise tool for people who wanted to incorporate hydrotherapy into their recovery program.