rogue

Universal Words noun, adjective noun 1 (humorous) a person who behaves badly, but in a harmless way: He's a bit of a rogue, but very charming. 2 (old-fashioned) a man who is dishonest and immoral: a rogues' gallery (= a collection of pictures of criminals) adjective [onlybeforenoun] 1 (of an animal) living apart from the main group, and possibly dangerous 2 behaving differently from other similar people or things, often causing damage: a rogue gene * a rogue police officer