put one's foot in one's mouth
Attested from 1887; from earlier put one's foot in it.
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put one's foot in one's mouth (third-person singular simple present puts one's foot in one's mouth, present participle putting one's foot in one's mouth, simple past and past participle put one's foot in one's mouth)
- (idiomatic) To misspeak, to say something embarrassing or wrong, or to make a mistake in public, or a social blunder, that is embarrassing or offensive. Nowadays usually put your foot in your mouth.