1. unintentionally say something foolish, embarrassing, or offensive
put your foot in your mouth by saying something you shouldn't
This expression means to say something tactless or embarrassing, usually at a bad moment. It expresses a form of regret and blame, as it is usually only done accidentally. Despite that, the result is often somebody being offended or upset, which can not only lead to your own embarrassment but can also get you into trouble. It can be used in a social and professional context but is more common as a social blunder. The variation 'put your foot in it' is more likely to be heard in the UK. Phrases with a similar meaning include 'make a faux pas,' and 'shoot yourself in the foot.'