ラテン語のcauda「尾」から。語源的にはcoda「行列」と同じ。もともとは、尻尾を股の間に挟んで逃げる動物のことだったが、後に臆病な人のことを指すようになった。
The identification of coward & bully has gone so far in the popular consciousness that persons & acts in which no trace of fear is to be found are often called coward(ly) merely because advantage has been taken of superior strength or position .... [Fowler]As a surname (attested from 1255) it represents Old English cuhyrde "cow-herd." Farmer has coward's castle "a pulpit," "Because a clergyman may deliver himself therefrom without fear of contradiction or argument."