muscle [LME] The ancient Romans saw a resemblance between a flexing muscle in the upper arm and the movements of a *mouse. Latin musculus, from mus ‘mouse’, meant ‘little mouse’ and also ‘muscle’. It entered English through French in the 14th century. The edible mollusc the mussel [OE] is the same word, and the accepted spellings of both words remained variable into the 19th century.