Trash mouth American slang
Used to refer to the tendency of using vulgar, nasty language.
I don't know why he has developed a bit of trash mouth recently. He used to be polite and nice
Used to refer to a person who uses vulgar, nasty language.
She didn't want her child to talk with that trash mouth.
Used to refer to the tendency of using insulting, offensive language.
As soon as he lost the game, he had quite a trash mouth with his opponent.
Used to refer to a person who uses insulting, offensive language.
You should accept your failure rather than become such a trash mouth.