watch (one's) mouth(redirected from Watch Your Mouth)
Also found in: Acronyms, Wikipedia.
watch (one's) mouth
To be very mindful or cautious about what one says; to control what one says in order to avoid offensive language. Watch your mouth! I don't care how you speak at home, that's not how we talk here. After being threatened with detention for my snide remarks in class, I knew I had to watch my mouth for the rest of the semester.