Slang. to speak critically and often disloyally of; disparage: Why do you bad-mouth your family so much?
Also, badmouth.
Origin: 1935–40; orig. a curse, spell (the sense recorded in Gullah); cf. Vai (Mande language of Liberia and Sierra Leone) dà nyà mà curse, lit., bad mouth
bad·mouth or bad-mouth (bād'mouth', -mouth') tr.v.
bad·mouthed or bad-mouthed, bad·mouth·ing or bad-mouth·ing, bad·mouths or bad-mouthsInformal To criticize or disparage, often spitefully or unfairly: "those cross-Atlantic aficionados who persistently idolize the British theater and bad-mouth Broadway"(Benedict Nightingale).
tv. to speak ill of someone or something. (See also dirty mouth; poor-mouth.) : I wish you would stop bad-mouthing my car.
n. someone who speaks ill of someone or something. : Harry is such a bad-mouth!
Dictionary of American Slang and Colloquial Expressions by Richard A. Spears.Fourth Edition. Copyright 2007. Published by McGraw Hill.
Cite This Source
"abuse someone verbally," 1941, probably ultimately from noun phrase bad mouth (1835), in black Eng., "a curse, spell," translating an idiom found in African and West Indian languages.