Definition of mouth off in US English:

mouth off

phrasal verb

informal
  • 1Talk in an unpleasantly loud and boastful or opinionated way.

    ‘he was mouthing off about society in general’
    • ‘Kids learn how to be mature only by mouthing off to any authority figure they can.’
    • ‘Maybe they've had a big boost in fundraising since he started mouthing off so publicly.’
    • ‘I'm sick of her mouthing off about me.’
    • ‘My nice neighbours the other side said that she'd been in there, mouthing off about her partner and asking for drink.’
    • ‘There is nothing wrong with people mouthing off on a radio talk show.’
    • ‘She was overheard mouthing off about her rival.’
    • ‘If a kid mouths off, maybe he doesn't like you or maybe he's seen his mother beaten up by her boyfriend.’
    • ‘If your father mouths off to you about it, just remind him that he lives in your house and has to respect your rules now.’
    • ‘If TV cameras catch him spitting or swearing, you can bet that some retired cop, headmaster or right-wing politician will be mouthing off to the Monday papers about sloppy role models and the decline of civilisation.’
    • ‘He was then booked for mouthing off to the assistant referee.’
    • ‘There were loads of lads mouthing off.’
    • ‘When he mouths off to a pretty young teacher, he apologizes: ‘I'm sorry I sounded off on you.’’
    • ‘I'm checking in with her today, and instead of mouthing off on what I think she should do, I'm just going to listen.’
    • ‘I wondered about how many of them actually think like they purport to rather than simply mouthing off in this obnoxious way simply to wind people up.’
    • ‘Nobody shows off or mouths off quite as good as a Leo.’
    • ‘He was just as into the avant-garde, but he was exploring it rather than mouthing off about it.’
    • ‘‘You're always mouthing off about things,’ one of my friends told me the other day as I launched an attack on the cost of school trips these days.’
    • ‘About half of them were prone to not listening to orders and mouthing off.’
    • ‘He was mouthing off about something he knows nothing about.’
    • ‘He skips school constantly and, on the handful of days he does show up, he's either mouthing off or getting into big-time, black-eye fights.’
    rant, spout, declaim, rave, jabber, sound off
    View synonyms
    1. 1.1mouth off at Loudly criticize or abuse.
      • ‘She had had to endure being mouthed off at all her childhood.’
      • ‘Some guy mouths off at him and they begin brawling.’
      • ‘He refused to go quietly, mouthing off at the coach as he made his way to the dressing room.’
      • ‘He was sent to cool off in the sin bin for mouthing off at the referee.’
      • ‘It was confirmed when you didn't mouth off at me earlier.’
      • ‘You can't just go mouthing off at people for making simple mistakes.’
      • ‘Before I get the chance to mouth off at her, she's in my face.’
      • ‘He thought that perhaps it wouldn't be such a smart idea to mouth off at the person holding the gun.’
      • ‘And so when someone blows up and mouths off at a guard or goes after somebody else about their kids, I totally understand where that emotion and that lightning-fast trigger comes from.’
      • ‘They are often petty offenders - kids who have been caught shoplifting, mouthing off at police, or using drugs a couple of times, for example.’
      • ‘She immediately got up and began mouthing off at the guy who had knocked me over.’
      • ‘He was only taken to the station because he mouthed off at a cop.’
      • ‘Never again, did Sean ever mouth off at him.’
      • ‘Then a person came across in a boiler suit and started mouthing off at us.’
      • ‘When Mr Godfrey started mouthing off at Sergeant Newell, he made us go with him to the station.’
      • ‘I thought you'd have mouthed off at the guards until they beat you to death.’
      • ‘After mouthing off at her, they turned it down a little bit, then a minute later cranked it up even louder than it was originally.’
      • ‘They're busy mouthing off at each other.’
      • ‘He mouths off at the ref, but can't even get a booking.’
      • ‘She's been like that ever since Lea turned around and started mouthing off at me.’