guy

a fall guy (mainly American, informal)

someone who is blamed for another person's mistake or crime. The book claims Lee Harvey Oswald didn't kill President Kennedy - he was just the fall guy.

See also: fall

No more Mr Nice Guy.

something that you say when you have decided to behave in a less pleasant way. I'm fed up with people taking advantage of me. From now on, it's no more Mr Nice Guy.

See also: more, nice

a wise guy (American & Australian, informal, American, very informal!)

someone who is always trying to seem more clever than everyone else in a way that is annoying. Okay, wise guy, if you're so damned smart, you can tell everyone how it's done! He's just some wise-ass who thinks he knows all the answers.

See also: wise

wise-guy (American & Australian, informal, American, very informal!)

a wise guy - someone who is always trying to seem more clever than everyone else in a way that is annoying. Hyde's wise-guy humour loses its charm after a few episodes. (always before noun)