n.
Pronunciation: ' m ə -s ə l
Function: noun
Etymology: Middle English muscle, from Old English muscelle, from Vulgar Latin *muscula, from Latin musculus muscle, mussel
Date: before 12th century
1 : a marine bivalve mollusk (esp. genus Mytilus ) usually having a dark elongated shell
2 : a freshwater bivalve mollusk (as of Unio, Anodonta, or related genera) that is especially abundant in rivers of the central U.S. and has a shell with a lustrous nacreous lining