gun·man \ˈgənmən, -ˌman, -ˌmaa(ə)n\noun (pluralgunmen) 1. a.: a man who is armed with or fires a gun; also: a guard armed with a gun b.: a man noted for his speed or skill in handling a gun in gunplay or gunfights 2.: a criminal whose crimes involve the use of a gun : killer; especially: one hired to kill another with a gun