[Fr., from L. tortus, twisted.] A creeping and swimming animal (so called from its crooked feet) covered with a hard shell, with openings for the head, legs, and tail. The tortoise is also called turtle, but this name is sometimes restricted to the marine species, tortoise to the land species, and terrapin to fresh-water species. Tortoises are mostly used for food ; and the green turtle, a marine animal, is extensively used for soup. The common box tortoise is more thoroughly protected than ordinary turtles, because it has joints at the bottom of the shell, and can draw up the under parts all round the edge of the box. - Tortoise shell. The shell of the hawk's-bill turtle, separated into thin plates, softened in hot water, and shaped in molds, in which it may be impressed with ornamental figures. It is used for combs, knife-handles, etc.