An insincere show of sympathy or sadness; crocodiles were once thought to “weep” large tears before they ate their victims: “Don't shed any crocodile tears for Fisher; I know you were responsible for his firing.”
An insincere display of grief, as in When the play's star broke her leg, her understudy wept crocodile tears. This term comes from the mistaken notion that crocodiles weep while eating their prey, one held in ancient Roman times. The actual term was picked up by Shakespeare and many other writers after him, and remains current.
[ Late 1500s