caimanEnglishOxford New American Dictionarycaiman /ˈkāmən, ˈkeɪmən / (also cayman) ▸ noun a semiaquatic reptile similar to the alligator but with a heavily armored belly, native to tropical America. Caiman and other genera, family Alligatoridae: three species, in particular the spectacled caiman (C. sclerops). – ORIGIN late 16th century : from Spanish caimán, Portuguese caimão, from Carib acayuman.