Definition of: prosimian

(prō·sim′ē·ən) adjective Zool.
Designating any member of a suborder or group (Prosimii) of widely distributed early primates, as lemurs, indris, lorises, and tarsiers, characterized by small size, primitive brain development, and extensive adaptive radiation.
—noun Any primate of this group. [<NL <Gk. pro- before + L simia an ape]