limpet

n. [ Prob. through French fr. L. lepas, -adis, Gr. lepa`s, -a`dos. ] (Zool.) 1. In a general sense, any hatshaped, or conical, gastropod shell. [ 1913 Webster ]

2. Any one of many species of marine shellfish of the order Docoglossa, mostly found adhering to rocks, between tides. [ 1913 Webster ]

☞ The common European limpets of the genus Patella (esp. Patella vulgata) are extensively used as food. The common New England species is Acmæa testudinalis. Numerous species of limpets occur on the Pacific coast of America, some of them of large size. [ 1913 Webster ]

3. Hence: Somthing or someone that clings tenaciously to another object or person; specifically a military explosive device having magnets allowing it to cling to a metallic target object, such as the hull of a ship. [ PJC ]

3. Any species of Siphonaria, a genus of limpet-shaped Pulmonifera, living between tides, on rocks. [ 1913 Webster ]

4. A keyhole limpet. See Fissurella. [ 1913 Webster ]