Per·i·win·kle n.  Zool. Any small marine gastropod shell of the genus Littorina.  The common European species (Littorina littorea), in Europe extensively used as food, has recently become naturalized abundantly on the American coast.  See Littorina.
 Note: ☞ In America the name is often applied to several large univalves, as Fulgur carica, and Fulgur canaliculata.