The image is of your mouth as a gun, and you're shooting it. This idiom means that you're speaking without thinking - just blasting out whatever comes to your mind.
I believe you are talking about "shooting your mouth off." It means talking too much, or talking when you don't know what you are talking about.
Rather than exaxt sentences, you need to look at the context to understand if someone was "shooting off their mouth". The boy spoke rudely to the teacher, but he slipped with a swear word that got him detention. The man complained about the check point, shooting off his mouth at the police officer, but the man's breathalizer registered 2.0. My friend always shoots her mouth off that I don't pick nice boyfriends, until a loser she dated dumped her.
Gleek or Gleeking
You get the ice arrow for shooting the dragon in the mouth
Talking excessively, usually spilling secrets.
what do you mean by not shooting right
A shooting iron is a gun.
he is an ancient being who once emerged from a donkeys mouth and now flies around shooting his sentient lasers from his mouth
blown up by the shooting of a propane tank in his mouth
It means to talk a lot without saying anything of value.
Nothing. Shoot OFF your mouth, however, means to say something ill-considered, usually something rude or aggressive. It's as if your mouth were a gun and you shot it without thinking.
Did they ever show you pictures of what it does to your mouth in school? Causes mouth cancer could have to get your tongue cut off can get white bumps in mouth. really bad on your teeth. just as bad.