受雇杀人的枪手
a person who is paid to shoot and kill someone
The hired gun turned out to be a police informant.
He was reluctant to talk about his work as a hired gun.
She attempted to have her former boss killed by a hired gun.
He insisted that the fighters weren't merely hired guns.
There were no international laws governing the use of hired guns on the battlefield.
See also: gun noun (FOR SHOOTING)