foul mouth(redirected from a foul-mouth)
1. Someone who often uses language considered profanity. I don't want that foul mouth watching our kids ever again—she taught them curse words!
2. adjective Describing someone who uses such language. Often hyphenated or spelled as one word. I had to kick some foul mouth kids out of the store today.
n. a person who uses obscene language habitually. Sally is turning into a real foul mouth.