mussel
mus.sel \'m*s-*l\ n [ME muscle, fr. OE muscelle; akin to OHG muscula mussel; both] often attrib fr. a prehistoric WGmc word borrowed fr. (assumed) VL muscula, fr. L musculus muscle, mussel 1: a marine bivalve mollusk (esp. genus Mytilus) usu. having a dark e longated shell 2: a freshwater bivalve mollusk (as of Unio, Anodonta, or relat ed genera) esp. abundant in rivers of the central U.S. having a shell with a lustrous nacreous lining