Wiktionary
alt. 1 (context informal English) A foul-mouthed person. 2 (context informal English) The obscene manner of speaking of a person who is foul-mouthed. n. 1 (context informal English) A foul-mouthed person. 2 (context informal English) The obscene manner of speaking of a person who is foul-mouthed.
Wikipedia
Guttermouth is an American punk rock band formed in 1988 in Huntington Beach, California and currently recording for Hopeless Records. They have released nine full-length studio albums and two live albums and have toured extensively, including performances on the Vans Warped Tour. They are infamous for their outrageous lyrics and behavior which are deliberately explicit, offensive and intended to shock, though usually in a humorous and sarcastic manner. This behavior has sometimes resulted in high-profile problems for the band, such as being banned from performing in Canada for eighteen months and leaving the 2004 Warped Tour amidst controversy over their political views and attitudes towards other performers.
Usage examples of "guttermouth".
If Owden could not handle Vangerdahast on his best behavior, she shuddered to think of the enmity that would be unleashed when the old guttermouth gave himself free rein.