Lemuria (Le-mu'-ri-a). An imaginary continent, also known as Amosnuria, beloved by science-fiction writers, that is alleged to have occupied most of the central Pacific Ocean until historic time, when it sank, leaving only the Pacific islands as tiny remnants. The dispersal of Polynesian peoples and cultures is supposed to have been facilitated by the existence of Lemuria, but this dispersal is easily explained otherwise. Geologically, the existence of such a continent, either modern or ancient, is impossible.