bad-mouth

IPA/ˈbæd maʊθ/
IPA/ˈbæd maʊθ/

bad-mouth — verb

  • bad-mouthpresent simple I / you / we / they
  • bad-mouthshe / she / it
  • bad-mouthedpast simple
  • bad-mouthing-ing form

1. to say critical or unkind things about a person or group when they are not prese

1.verbtransitiveB2
Definition

to say critical or unkind things about a person or group when they are not present, often in a way that is unfair or exaggerated

Example

Shirin refused to bad-mouth her former boss during the job interview.

negative pattern: refuse to bad-mouth [someone]

The coach warned the players not to bad-mouth their teammates to the press.

infinitive pattern: warn + not to + bad-mouth [someone]

Common collocations
  • bad-mouth [someone] behind [their] back
  • bad-mouth [someone] to [someone else]
  • constantly/repeatedly/always bad-mouth
  • never bad-mouth
  • stop bad-mouthing
Synonyms
  • speak ill of

    more formal and slightly old-fashioned; less direct than bad-mouth

  • run down

    same informal register; often implies persistent, unfair criticism

  • disparage

    formal register; focuses on belittling the value or worth of someone

  • trash-talk

    very informal, especially in sports or competition contexts

Antonyms
  • praise

    general opposite; express approval rather than criticism

  • compliment

    specific positive statement, the opposite of bad-mouthing

  • speak well of

    directly opposite construction; to say good things about someone

Grammar Patterns

bad-mouth + noun phrase (person or group)

Usage Note

Informal register; the object is usually a person or group that is not present. The gerund form (bad-mouthing) is common after prepositions and in continuous tenses.

Common Mistakes

The manager bad-mouthed her assistant to her face.
The manager criticized her assistant to her face.
bad-mouth implies speaking behind the person's back, not directly to them.
My sister bad-mouthed about the food.
My sister bad-mouthed the food.
bad-mouth is transitive; no preposition needed.

Word family

Synonym discussion

Sense: verb/1

All four expressions mean to criticize someone, but they differ in register and connotation. Bad-mouth is informal and suggests unfair or exaggerated talk behind the person's back — for example, a colleague bad-mouthing the new manager in the break room. Run down is also informal but implies persistent criticism that wears the subject down, as when a parent constantly runs down their child's choices. Disparage is formal and focuses on belittling worth or quality, often in a public or written context: a critic might disparage a novel's plot. Speak ill of is somewhat old-fashioned and carries a moral tone, as in the proverb 'Do not speak ill of the dead.' In everyday conversation, bad-mouth and run down are the most natural choices; disparage belongs in speeches and essays.

bad-mouth ↗run down ↗disparage ↗speak ill of ↗

Common collocations

Nouns

Adverbs

Phrases

  • behind someone's back
  • to anyone who will listen

Prepositions

Etymology

Old EnglishEnglish

The verb bad-mouth is formed by converting the noun phrase 'bad mouth' (someone who habitually speaks ill of others, attested since the early 1900s) into a verb. The noun phrase itself combines the adjective 'bad' with 'mouth' (speech organ). The verb form entered mainstream American English in the mid-20th century, likely influenced by African American English usage, and became common in informal contexts by the 1970s.

First known use

1933

1933, in the meaning defined above