卸磨殺驢 [ㄒㄧㄝˋ ㄇㄛˋ ㄕㄚ ㄌㄩˊ; xie4 mo4 sha1 lu:2] lit. to kill the donkey when the grinding is done (idiom) to get rid of sb once he has ceased to be useful ◄ ►