Definition of certain in English:



  • 1Able to be firmly relied on to happen or be the case.

    ‘it's certain that more changes are in the offing’
    ‘she looks certain to win an Oscar’
    • ‘Mr Brown was certain to win the seat, the only question was the size of the majority.’
    • ‘The only certain thing is that the next record will sound nothing like it.’
    • ‘No credible alternative will brave the embarrassment of certain heavy defeat.’
    • ‘On the contrary, its effect was certain to be that more people were injured and killed in accidents.’
    • ‘A vote on this issue was withdrawn last week, as it was certain to be defeated.’
    • ‘It acts as a certain guarantee for the freedoms a writer needs, such as the air to breathe.’
    • ‘It was wryly noted that the heavens had delivered the Scots from certain defeat.’
    • ‘The effort was no more than the home side deserved at that stage and it seemed certain that they would go on to win.’
    • ‘There's no more sure and certain indication that you're not in control than this.’
    • ‘First, we must recognise that faith to appropriate God's abundance is certain to be tested.’
    • ‘His job is not to convince them to vote for him on Tuesday in the first ballot - he is almost certain to win that vote.’
    • ‘It will be hard, and it may not ensure victory, but any other way is certain defeat.’
    • ‘Hope is that certain and unfailing goal that God has set before His children.’
    • ‘If Asda does push ahead with the new format, it is certain to test the concept first.’
    • ‘One thing is certain though, the trust will no longer have my support in any form.’
    • ‘Kent were all out for 339 and Somerset had rescued a victory from almost certain defeat.’
    • ‘The chase is over almost before it has begun and Freya's grip is sure and certain.’
    reliable, dependable, trustworthy, sound, foolproof, tested, tried and tested, effective, efficacious, guaranteed, sure, unfailing, infallible, unerring
    unquestionable, sure, definite, beyond question, not in question, not in doubt, beyond doubt, unequivocal, indubitable, undeniable, irrefutable, indisputable, incontrovertible, incontestable, obvious, patent, manifest, evident, plain, clear, transparent, palpable, unmistakable, conclusive, recognized, confirmed, accepted, acknowledged, undisputed, undoubted, unquestioned, unchallenged, uncontested
    sure, very likely, bound, destined, predestined, fated, trusted, assured of doing something
    inevitable, assured, destined, predestined, fated
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    1. 1.1Having or showing complete conviction about something.
      ‘are you absolutely certain about this?’
      • ‘Whatever the future holds, the one thing he can be certain about is how much he will miss Blackburn Rovers.’
      • ‘I woke up this morning so bloody sure of everything and now am slightly less certain.’
      • ‘Widdecombe does, though, concede that it is hard to be certain about what never happened.’
      • ‘If you can't be certain about that then how can you be certain about anything?’
      • ‘If one thing is certain about the war in Iraq, it is that lawyers are making a packet.’
      • ‘I am not certain about that, your Honour, but my belief is that it did not go on appeal.’
      • ‘It is a very old poem from 1994 and not even I am certain about the origin of much of it.’
      • ‘OK, that was a bit strong, and I am actually much less certain about the issue than that.’
      • ‘Of course nobody can be certain about future developments and how the trade union leaders will act.’
      • ‘If you aren't sure about total numbers you can still send us a booking for those you are certain about.’
      • ‘I am sure that after today's antics you are quite certain about what I did all day long.’
      • ‘He is just as certain about this as he is about wanting to reach his sporting potential as an adult, not as a teenager.’
      • ‘Take out a piece of paper and write down the things you are pretty much certain about.’
      • ‘Surely that would be as big a torment to the families of his victims as the certain knowledge that they will never know.’
      • ‘As with the gospel as a whole, it is impossible to be certain about earlier stages of composition.’
      • ‘I am not certain about this particular rendition will taste, only time will tell.’
      • ‘What I miss is the certain knowledge that if only she would quit, the world would be a better place.’
      • ‘Ella Lockett from Bassett Green admitted she wasn't certain about joining the group.’
      • ‘Ad folk need to be certain about who and how many people they are reaching.’
      • ‘That is a fact that we can be certain about without having to be a marlin to know it.’
      sure, confident, positive, convinced, in no doubt, unshaken in one's belief, secure in one's belief, easy in one's mind, satisfied, assured, persuaded
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  • 2[attributive] Specific but not explicitly named or stated.

    ‘he raised certain personal problems with me’
    ‘the exercise was causing him a certain amount of pain’
    • ‘I think when you play a character you have to be able to relate to certain aspects.’
    • ‘As a male I have never been able to understand why a certain variety of my own sex cannot take defeat by a woman.’
    • ‘Yet, they keep winning, whilst certain pretenders have experienced a few slips.’
    • ‘Many anglers did not renew in April because they weren't able to fish in certain areas.’
    • ‘Depending on the status of the field only certain units may be able to operate from the area.’
    • ‘I'm not trying to sound like a saint, but we take for granted that we are healthy and able to live a certain way.’
    • ‘If you do this out of necessity rather than choice you may be able to claim certain running costs.’
    • ‘If we had stuck a few more phases on certain moves the win would have been more comfortable.’
    • ‘In this connection the Bank relies on certain observations of Lord Steyn in Williams v.’
    • ‘They knew that a just society relies on a certain level of order and cohesiveness.’
    • ‘The Employer's pleading relied on certain express and implied terms of the contract.’
    • ‘He also relied upon certain paragraphs in the Guidance issued by the Secretary of State.’
    • ‘Those who do not have a problem will be able to pick out certain numbers or shapes from within the dot patterns.’
    • ‘In certain conditions he is able to see the fate of those who have disappeared.’
    • ‘If you want a certain party to win, it is better that you persuade many others to vote for them than vote yourself.’
    • ‘For every advanced feature added, I increasingly expect to be able to do certain things.’
    • ‘Life is not just about living and dying and as such we all should be able to enjoy a certain quality of life.’
    • ‘Tricks have no value in themselves; the object is to win tricks with certain cards in them.’
    • ‘Since he won Pop Idol, certain areas of the media have sought to blame Young for all the world's ills.’
    • ‘Foreigners know that you need experience in your field to able to have a certain job.’
    determined, definite, fixed, established, precise, defined, exact, explicit, express
    particular, specific, individual, special, especial
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    1. 2.1Used when mentioning the name of someone not known to the reader or hearer.
      ‘a certain General Percy captured the town’
      • ‘And this was a plagiarism from a certain Mr. "Toe" King, so called from this invention!’
      • ‘When a certain Mr. Po assisted with military affairs on the northern frontier, he obtained a well-bred horse to give to me.’
      • ‘I saw a certain Mr. Drewett walking in the direction of Wall-street, and had the charity to tell him you would be at home in ten minutes.’


  • Some but not all.

    ‘certain of his works have been edited’
    • ‘I will attempt to suggest certain of the most crucial themes of that debate.’
    • ‘In certain of the cases above, a necessary division of labor may occur within the task.’
    • ‘EU citizens from other countries can vote in certain of our elections.’
    • ‘The significant element of the film comes in the comments of certain of the documentary film-makers.’
    • ‘My sense of humour used to be so dry that it was sometimes impossible to know how to take certain of my comments.’


  • for certain

    • Without any doubt.

      ‘I don't know for certain’
      • ‘If anything is known for certain, it is only that the deal was virtually inevitable.’
      • ‘One thing is for certain - if this lady blows her top, many will not be happy about it.’
      • ‘I can't find any trace of this, so can't for certain say whether it is or isn't true.’
      • ‘No one can say for certain whether or not there are further rate rises on the way.’
      • ‘One cannot say for certain whether it would reach the proportion which it had in the past decade.’
      • ‘We do not know for certain whether heading the ball in soccer may result in chronic cognitive impairment.’
      • ‘It's impossible to say for certain whether this girl survived because of her treatment or in spite of it.’
      • ‘We will not know for certain till 2001 when figures on cattle with BSE are collected.’
      • ‘In bright sunlight, with cameras all around the ground, no one could say for certain what had happened.’
      • ‘It is too early to say for certain whether we are on the verge of a major breakthrough.’
      certainly, for certain, for sure, to be sure, definitely, undoubtedly, without doubt, doubtless, beyond any shadow of a doubt, beyond the shadow of a doubt, indubitably, unquestionably, incontestably, irrefutably, incontrovertibly, undeniably, without fail, inevitably, unavoidably
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  • make certain

    • 1[with clause]Take action to ensure that something happens.

      ‘make certain Lewis knows all the facts’
      ‘I made certain that our paths would never cross again’
      • ‘For tenants this is a new situation and great care must be taken to make certain that every factor is properly dealt with.’
      • ‘If you do pull weeds, the only way to ensure the plant won't come back is to make certain the entire root system is removed.’
      • ‘As the manufacturer of one of the most popular vehicles out in today's roads and highways, the Ford Motor Company has made certain that they would ensure quality, safe, and reliable vehicles.’
      • ‘I told the person caring for him to make certain that coin went with him to his room.’
      • ‘General Powell had learned his lesson from the Panama invasion and ensured not only media access but made certain the right kind of spokesman stood before the camera lens before the American audience.’
      • ‘At the beginning of class, the teachers made certain everyone had instructional materials and supplies as they ensured no one was left out.’
      • ‘The duty on the company in this case was to ensure, ie to make certain, that persons are not exposed to risk.’
      • ‘This is all about ensuring, making certain that every legal vote counts.’
      • ‘If you make up your mind to live from writing, it is prudent to make certain that your work is good, he added.’
      • ‘And we have to make certain that we're properly taken care of from a defense perspective.’
      make sure, ensure, see to it
      confirm, check, verify, corroborate, establish
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      1. 1.1Establish whether something is definitely the case.
        ‘he probably knew her, but it didn't do any harm to make certain’
        • ‘He also examined her to make certain she could bear the child without suffering undo strain.’
        • ‘He waited until all his children had grown up and left home before running for Council, and, even then, made certain his family was supportive of his foray into municipal politics.’
        • ‘The only useful use of Galileo is to make certain whether or not the football crossed the goal line!’
        • ‘It entails, for instance, making certain that a nearby aquifer can adequately support the local population's long-term water needs before tapping the source and constructing a water system.’
        make sure, ensure, see to it
        confirm, check, verify, corroborate, establish
        View synonyms
  • of a certain age

    • No longer young (used politely or euphemistically)

      ‘women of a certain age swooned over his acerbic wit’
      ‘men of a certain age who still dream that they might have been a great football player in their youth’
      • ‘The enterprise will bring back memories to people of a certain age who remember a coffee bar in the shop next door when rock'n'roll was young.’
      • ‘Being of a certain age and background, I was wont to sport the occasional safety pin back in my teens.’
      • ‘It was full of ladies of a certain age in flowery swimming caps.’
      • ‘"I have some very lovely letters from gentlemen of a certain age," she says.’
      • ‘Women of a certain age and economic status are no longer willing to settle and simper.’
      • ‘You have to be of a certain age even to know who that is.’


Middle English: from Old French, based on Latin certus settled, sure.