n. One of several different freshwater or tide-water tortoises of the family Emydidæ; specifically, in the United States, the diamond-back, Malaclemmys or Malacoclemmys palustris, of the Atlantic coast from New York to Texas, famous among epicures. See diamond-backed turtle (under diamond-backed), and Malaclemmys.n. Some other tortoise or turtle: as, the elephant terrapin of the Galapagos.n. A dish made of the diamond-back.