mouth off(redirected from mouths off)
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1. To speak without discretion; to speak too loudly or freely, especially about sensitive topics or information. We would have gotten away with our plan if your dumb cousin hadn't started mouthing off all over town.
2. To make disrespectful comments; to sass someone. You're going to get detention again if you keep mouthing off to your teacher.
to speak out of turn; to backtalk. If you mouth off, I will ground you for three weeks. Don't mouth off at me, buster!
1. Complain or express one's opinions loudly and indiscreetly, as in She was always mouthing off about the other members. [Slang; 1960s]
2. Speak impudently, talk back, as in He got in trouble by mouthing off to his teacher. [Slang; 1960s]
To express one's opinions or complaints in a loud, indiscreet manner: Quit mouthing off about what you think is wrong, and go do something about it! Don't mouth off to your parents like that!
in. to give (someone) back talk. If you mouth off, I will ground you for three weeks.