Teguexin \Te*guex"in\, n. (Zo["o]l.) A large South American lizard ({Tejus teguexin}). It becomes three or four feet long, and is blackish above, marked with yellowish spots of various sizes. It feeds upon fruits, insects, reptiles, young birds, and birds' eggs. The closely allied species {Tejus rufescens} is called {red teguexin}.