Definition of slip up in English:

slip up

phrasal verb

informal
  • Make a careless error.

    ‘they often slipped up when it came to spelling’
    • ‘With closest rivals Radcliffe Borough and Eastwood Town continually slipping up in their bid to catch up on the runaway leaders, John Reed's men now have a nine-point advantage and at least four games in hand.’
    • ‘While most of their main rivals were slipping up, the Tanners beat 10-man Dulwich Hamlet 2-1 on Saturday.’
    • ‘Now one vaccine manufacturer slipping up would not be a major problem if there were lots more manufacturers ready to step into the breach.’
    • ‘I have done December and January, I slipped up on February - the short month passing by as I waited for a good day that never came.’
    • ‘His Liverpool team is showing signs of improvement with every game that hint of even better things to come next season, and with Leeds slipping up again, second place in the Premiership is not such a fanciful notion.’
    • ‘Charles Kennedy may have slipped up on a tax question at their policy briefing, but this was probably down to sleep deprivation after the birth of his new baby son!’
    • ‘He never slips up, because he is a world-class survivor of media onslaught.’
    • ‘Was there not enough space to print the truth or has someone been slipping up on their research skills?’
    • ‘At the end, the Chinese mistress of ceremonies slipped up by saying ‘goodbye’ in Japanese.’
    • ‘They had slipped up in regard to Mr. Egan's date of birth, Mr. Collins said.’
    • ‘There is of course many a slip twixt the cup and the lip but really it borders on the impossible to visualise them slipping up this time.’
    • ‘It will have occurred in one of the local borough support offices, where somebody has slipped up and not informed that officer, and there can be no excuse for it.’
    • ‘She only feels ill when she slips up and eats dairy products.’
    • ‘As these volumes demonstrate, scholars take endless pleasure in drawing attention to the great man's shortcomings, as it is in the moments when he slips up that Holmes becomes almost human.’
    • ‘It is said in Washington that a gaffe is when someone slips up and tells the truth.’
    • ‘But she slipped up and gave a secret about whether she and her husband Ben Affleck are expecting a boy or a girl.’
    • ‘He seemed forever on edge, worried about slipping up or uttering something to upset the assembled crowd.’
    • ‘Usually they just let you keep slipping up, spending more than you have in your account so that they can slap on the €12.70 bounced cheque fee or the hefty interest surcharge if you become overdrawn.’
    • ‘The boy pretends he is a lawyer but keeps slipping up.’
    • ‘So I slipped up a bit, having a bit more caffeine than I probably should, but only when on vacation and with family.’
    make a mistake, blunder, make a blunder, get something wrong, miscalculate, make an error, trip up, err, go wrong
    make a bloomer, make a boo-boo, screw up, make a howler, muff something up
    boob, cock something up, drop a clanger
    goof up
    View synonyms