foot-in-mouth disease
A tendency to make remarks that are embarrassingly wrong or inappropriate.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He always says the wrong thing because he has foot-in-mouth disease.”
“You often suffer from foot-in-mouth disease when you are nervous.”
“Does he have foot-in-mouth disease or is he just mean?”
“I really tried to be polite at the dinner party, but my foot-in-mouth disease made me insult the host's cooking.”
“My brother has a bad case of foot-in-mouth disease and accidentally told our mother about her surprise birthday party two weeks early.”
“She was doing well in the interview until her foot-in-mouth disease kicked in and she started complaining about her previous manager.”
“Despite his best intentions to remain diplomatic during the negotiations, his chronic foot-in-mouth disease caused him to offend the delegates with an ill-timed joke.”
The idiom arose as a humorous conflation of the veterinary ailment foot-and-mouth disease and the established expression to put one's foot in one's mouth. It applies the phonological structure of the former to the social consequences of the latter.
Last updated August 10, 2026