primates: an order of omnivorous mammals, consisting of three suborders: Anthropoidea, including humans, great apes, gibbons, and Old World and New World monkeys; Prosimii, including lemurs, loris, and the like; and Tarsioidea, including tarsiers; members of this order are characterized by highly developed brains, forward directed eyes, use of the hands, and varied locomotion, and particularly by complex, flexible behavior involving a high level of social interaction and adaptability.