mandrill \man"drill\ (m[a^]n"dr[i^]l), n. [Cf. F. mandrille, Sp. mandril, It. mandrillo; prob. the native name in Africa. Cf. {Drill} an ape.] (Zool.) A large West African baboon ({Papio sphinx} syn. {Mandrillus sphinx}, formerly {Cynocephalus mormon} syn. {Papio mormon}). The adult male has, on the sides of the nose, large, naked, grooved swellings, conspicuously striped with blue and red. It is an endangered species. [1913 Webster +PJC]