noun
Etymology: so called from its being small and arboreal
1. : any of several small soft-haired So. American monkeys of the genus Saimiri (syn. Chrysothrix ) ; especially : a monkey ( S. sciurea ) having a long nonprehensile tail and being chiefly yellowish gray in color with a white face and black nose
2. : titi
3. : tamarin ; especially : a Panamanian tamarin ( Leontocebus geoffroyi )