What is the meaning of the idiomatic expression 'cut it out'?

"Stop it right now!"

When you tell someone, "cut it out!" you're not telling them to get a knife and start dissecting. This is an irritated phrase that you use when someone is doing something annoying, dangerous, or anything in general that they shouldn't do. You are telling them to "cut" that behavior or action out of their act.

In other Words, you're telling them, "Stop it right now!"