There are several synonyms for the commonly used phrase "shut your mouth/face". Some of these include "be quiet", "hush up", "zip it", "shush", "quiet down", "stop talking", "cease speaking", or "keep quiet". Each of these phrases can effectively convey the message of asking someone to stop talking or being quiet. It's important to remember to use these phrases in a respectful way and to always be mindful of how our words impact others. Whether it's a friendly reminder to keep things quiet or a stern warning to stop talking altogether, there are many ways to communicate effectively without resorting to harsh language.