cer·​tain | \ˈsər-tᵊn \

Definition of certain 

(Entry 1 of 2)

1 : fixed, settled a certain percentage of the profit

2 : of a specific but unspecified character, quantity, or degree the house has a certain charm

3a : dependable, reliable a certain remedy for the disease

b : known or proved to be true : indisputable it is certain that we exist

4a : inevitable the certain advance of age

b : incapable of failing : destined used with a following infinitive she is certain to do well

5 : assured in mind or action I am certain they are right

for certain

: as a certainty : assuredly the cause is not known for certain

of a certain age

: of a somewhat advanced age : no longer young remembered by people of a certain age

Definition of certain (Entry 2 of 2)

: certain ones certain of my generation— W. B. Yeats

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Choose the Right Synonym for certain


sure, certain, positive, cocksure mean having no doubt or uncertainty. sure usually stresses the subjective or intuitive feeling of assurance. felt sure that I had forgotten something certain may apply to a basing of a conclusion or conviction on definite grounds or indubitable evidence. police are certain about the cause of the fire positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it. I'm positive that's the person I saw cocksure implies presumptuous or careless positiveness. you're always so cocksure about everything

Examples of certain in a Sentence


I'm fairly certain that I'll be on time. a certain person told me that today is your birthday

Recent Examples on the Web: Adjective

And the ministers asked the United States to refrain from punishing firms in certain commercial sectors, including energy, auto manufacturing, aviation, infrastructure and pharmaceuticals. NBC News, "U.S. refuses European requests for exemptions from its new sanctions on Iran," 14 July 2018 McSorley shotputs the ball a bit but is mobile and made some brilliant tight-window throws last year—many of them went unnoticed thanks to a certain backfield mate. Saturday, Sept. 29, time and network TBD Amon G. Carter Stadium, Fort Worth, Tx. Conor Orr, SI.com, "An NFL Fan’s Viewing Guide to the 2019 College Football Season," 13 July 2018 However, the franchise’s reliance on certain visual effects techniques took away one of McKellen’s favorite things about acting—the interplay and in-the-moment relationships between actors. Nathan Mattise, Ars Technica, "In new documentary, Ian McKellen reflects on Magneto, Gandalf," 8 July 2018 The team’s hope was the direction would be certain by now, that the only thing left to do at this point would be figuring out the finer details of the brown uniforms the Padres would be playing in come 2020. Kevin Acee, sandiegouniontribune.com, "Padres find they can't turn all blue eyes brown, but ...," 14 July 2018 Miller is certain to land on the disabled list and undergo tests on his elbow. Nick Piecoro, azcentral, "Diamondbacks' Shelby Miller departs early with right elbow tightness," 11 July 2018 This presentation gives a general overview of certain rules related to Social Security and ideas to help a person maximize their benefits. Courant Community, "Community News For The Windsor Locks Edition," 10 July 2018 Even the ones who were there, they were all pretty much only allowed to play certain kinds of roles. James Hebert, sandiegouniontribune.com, "For theater community, finding ways to reflect societal diversity onstage is more urgent than ever," 13 July 2018 There’s a certain kind of pleasure in really feeling for someone else, even if those feeling are bad. Brian Resnick, Vox, "A sociologist explains why we make spectacle out of trauma like the Thai cave boys," 11 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'certain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of certain


13th century, in the meaning defined at sense 1

Pronoun, plural in construction

15th century, in the meaning defined above

History and Etymology for certain


Middle English certeyn, certayne, borrowed from Anglo-French certein, certain, going back to Vulgar Latin *certānus, from Latin certus "fixed, settled, indisputable," originally past participle of cernere "to sift, discern, decide, determine" (going back to an Indo-European present stem *kri-n-, verbal adjective *kri-to-, from a verbal base *krei̯̯̯(h1)- "sift, separate," whence Greek krī́nein "to separate, choose, decide," verbal adjective kritós, Welsh gogrynu "to sift") + -ānus + -an entry 2

Pronoun, plural in construction

Middle English certyn, derivative of certeyn certain entry 1 — see certain entry 1

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Statistics for certain

Last Updated

8 Nov 2018

Look-up Popularity

Time Traveler for certain

The first known use of certain was in the 13th century

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More Definitions for certain



English Language Learners Definition of certain

: not having any doubt about something : convinced or sure

—used with it to say that something is known to be true or correct

—used to refer to something or someone that is not named specifically


cer·​tain | \ˈsər-tᵊn \

Kids Definition of certain

 (Entry 1 of 2)

1 : without any doubt : sure Are you certain you saw her?

2 : known to be true It's certain that they were here.

3 : known but not named A certain person told me.

4 : being fixed or settled a certain percentage of the profit

5 : bound by the way things are Our plan is certain to succeed.

6 : sure to have an effect a certain cure



Kids Definition of certain (Entry 2 of 2)

: known ones that are not named Certain of the students could work harder.

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Comments on certain

What made you want to look up certain? Please tell us where you read or heard it (including the quote, if possible).


by force of circumstances

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