n. [ F. marmouset a grotesque figure, an ugly little boy, prob. fr. LL. marmoretum, fr. L. marmor marble. Perhaps confused with marmot. See Marble. ] (Zool.) Any one of numerous species of small South American monkeys of the genera Hapale and Midas, family Hapalidae. They have long soft fur, and a hairy, nonprehensile tail. They are often kept as pets. Called also squirrel monkey. [ 1913 Webster ]