purpura

‖n. [ L., purple, purple fish: cf. F. purpura. See Purple. ] 1. (Med.) A disease characterized by livid spots on the skin from extravasated blood, with loss of muscular strength, pain in the limbs, and mental dejection; the purples. Dunglison. [ 1913 Webster ]

2. (Zool.) A genus of marine gastropods, usually having a rough and thick shell. Some species yield a purple dye. [ 1913 Webster ]