Lily-livered Meaning

Example : 1606, William Shakespeare, King Lear, act 2, sc. 2:  . . . a lily-livered, action-taking knave . . . ; one that wouldst be a bawd, in way of good service, and art nothing but the composition of a knave, beggar, coward, pandar, and the son and heir of a mongrel bitch.1850, William Makepeace Thackeray, The History of Pendennis, ch. 61:  "But as for that lily-livered sneak—that poor lyin' swindlin' cringin' cur of a Clavering—who stands in my shoes—stands in my shoes, hang him!"