[platy] adj (1533): resembling a plate; also: consisting of plates or flaky layers--used chiefly of soil or mineral formations
[2]platy n, pl platy or plat.ys or plat.ies [NL Platypoecilus, former genus name of the fish] (1931): either of two live-bearers (Xiphophorus maculatus and X. variatus of the family Poeciliidae) that are popular aquarium fishes and are noted for variability and brilliant color--called also platyfish