"Cut it/that out" is a phrase commonly used to tell someone to stop doing something irritating or inappropriate. However, there are several synonyms that can be used to convey the same message. For example, "knock it off," "cease and desist," "halt," "quit it," "desist," "refrain," and "stop it" are all alternative phrases that can be used to tell someone to stop their behavior. Using synonyms can help to express the same message in a different way, making the language more interesting and varied. Ultimately, the aim is to communicate the message effectively, and using synonyms can help to achieve that.