What is "tripedalism"

Tripedalism (from the Latin tri = three + ped = foot) is locomotion by the use of three legs. There are no known species where three legs are standard, although the movement of some macropods such as kangaroos, which can alternate between resting their weight on their muscular tails and their two hind legs, may be an example of tripedal locomotion in animals. There are also the tripod fish. Several species of these fish rest on the ocean bottom on two rays from its two pelvic fins and one ray from its caudal fin (1).

Tripedalism contrasts with the common bipedalism of two-legged animals and quadrupedalism of four-legged animals.