mussel (n.)

"edible bivalve mollusk," Middle English muscle, from Old English muscle, musscel, from Late Latin muscula (source of Old French musle, Modern French moule, Middle Dutch mosscele, Dutch mossel, Old High German muscula, German Muschel), from Latin musculus "mussel," literally "little mouse," also "muscle;" like muscle, derived from mus "mouse" on the perceived similarity of size and shape (see mouse (n.)). The modern spelling, distinguishing the word from muscle, is recorded from c. 1600 but was not fully established until 1870s.