Definition of certain in English:

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Pronunciation: /ˈsərtn/


1Known for sure; established beyond doubt: it’s certain that more changes are in the offing she looks certain to win an Oscar
More example sentences
  • A vote on this issue was withdrawn last week, as it was certain to be defeated.
  • It was wryly noted that the heavens had delivered the Scots from certain defeat.
  • It will be hard, and it may not ensure victory, but any other way is certain defeat.
unquestionable, sure, definite, beyond question, not in doubt, indubitable, undeniable, irrefutable, indisputable;
obvious, evident, recognized, confirmed, accepted, acknowledged, undisputed, undoubted, unquestioned
sure, very likely, bound, destined
inevitable, assured, destined, predestined;
unavoidable, inescapable, inexorable, ineluctable
informal in the bag
reliable, dependable, trustworthy, foolproof, tried and tested, effective, guaranteed, sure, unfailing, infallible
informal sure-fire, idiot-proof, goof-proof
1.1Having complete conviction about something; confident: are you absolutely certain about this? true and certain knowledge of the essence of existence
More example sentences
  • Whatever the future holds, the one thing he can be certain about is how much he will miss Blackburn Rovers.
  • Ella Lockett from Bassett Green admitted she wasn't certain about joining the group.
  • He is just as certain about this as he is about wanting to reach his sporting potential as an adult, not as a teenager.
sure, confident, positive, convinced, in no doubt, satisfied, assured, persuaded
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
More example sentences
  • Depending on the status of the field only certain units may be able to operate from the area.
  • For every advanced feature added, I increasingly expect to be able to do certain things.
  • 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.
determined, definite, fixed, established, precise
particular, specific, individual, special
2.1Used when mentioning the name of someone not known to the reader or hearer: a certain General Percy captured the town
More example sentences
  • And this was a plagiarism from a certain Mr. "Toe" King, so called from this invention!
  • 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.
  • When a certain Mr. Po assisted with military affairs on the northern frontier, he obtained a well-bred horse to give to me.


(certain of)
Some but not all: certain of his works have been edited
More example sentences
  • EU citizens from other countries can vote in certain of our elections.
  • My sense of humour used to be so dry that it was sometimes impossible to know how to take certain of my comments.
  • In certain of the cases above, a necessary division of labor may occur within the task.



for certain

Without any doubt: I don’t know for certain
More example sentences
  • 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.

make certain

[with clause] Take action to ensure that something happens or is the case: I made certain that our paths would never cross again
More example sentences
  • This is all about ensuring, making certain that every legal vote counts.
  • The duty on the company in this case was to ensure, ie to make certain, that persons are not exposed to risk.
  • 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.
2.1Establish whether something is definitely correct or true: he probably knew her, but it didn’t do any harm to make certain
More example sentences
  • The only useful use of Galileo is to make certain whether or not the football crossed the goal line!
  • 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.


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

Words that rhyme with certain


For editors and proofreaders

Syllabification: cer·tain

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