Baboon \Bab*oon"\, n. [OE. babewin, baboin, fr.F. babouin, or LL. babewynus. Of unknown origin; cf. D. baviaan, G. pavian, baboon, F. babin lip of ape, dogs, etc., dial. G. b["a]ppe mouth.]

(Zo["o]l.) One of the Old World Quadrumana, of the genera Cynocephalus and Papio; the dog-faced ape. Baboons have dog-like muzzles and large canine teeth, cheek pouches, a short tail, and naked callosities on the buttocks. They are mostly African. See Mandrill, and Chacma, and Drill an ape.

Source: Webster's Revised Unabridged Dictionary (1913)