Muscle: Is actually a word we’ve borrowed from the French, which has its roots in the Latin word ‘musculus’, ‘mus’ refered to a mouse and ‘sculus’ meant little. So the word literally meant ‘little mouse’; the Romans felt that the movement of muscles resembled the movements of little mice under the skin. This is idea that they likely got from the Greeks, who used the same word ‘mys’ for both ‘mouse’ and ‘muscle’. ‘Mys’ incidentally, is the root of the modern medical prefix ‘myo’, which is used in reference to muscles.