cer·​tain | \ ˈsər-tᵊn How to pronounce certain (audio) \

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 infinitiveshe 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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Synonyms for certain

Synonyms: Adjective

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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

Adjective 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 The near-certain guarantee of an agonizingly slow vote count is one reason to hope that, whatever the outcome, the 2020 election doesn’t all come down to Arizona. John Mccormack, National Review, "Election: Battleground Arizona," 17 Sep. 2020 However, depending on the facility, only a certain amount of swimmers can be on the pool deck or in the facility at a time. Shawn Mcfarland, courant.com, "What’s different about the fall high school season in Connecticut? Here’s how each sport has been affected by the pandemic," 16 Sep. 2020 His relative plunge has been mitigated by the rise of other Twins relief pitchers and a deep roster that has forged ahead to carve out a 30-19 roster and near-certain playoff berth. Michael Rand, Star Tribune, "Has Twins closer Taylor Rogers been bad, unlucky or a little of both?," 15 Sep. 2020 Likewise, Broad co-leader François Aguet and colleagues confirmed certain eQTLs extend their reach to distant genes, even those on other chromosomes. Elizabeth Pennisi, Science | AAAS, "‘Invaluable’ database helps solve mystery of how genes are regulated," 10 Sep. 2020 Some checking accounts will waive a certain amount of overdraft fees each year, while other high-end accounts might not charge any fees at all. Jennifer Yellin, CNN Underscored, "How to choose the best checking account," 10 Sep. 2020 The Colts are viewed as a likely -- but not certain -- playoff team as Week 1 arrives. Scott Horner, The Indianapolis Star, "NFL power rankings Week 1: Colts viewed as likely playoff contenders," 9 Sep. 2020 In Game 5, with the Cards up 3-2 in the top of the fifth and leading the series 3-1, Brock doubled with one out and seemed certain to score when Julian Javier lined a single to left. CBS News, "Lou Brock, Hall of Fame outfielder, has died at 81," 6 Sep. 2020 There are plenty of other people whose faith is just as strong, whose belief in God’s plan is just as certain, who have put their trust in science. Nancy Armour, USA TODAY, "Opinion: Kirk Cousins' comments on COVID-19 danger to public health, not personal belief," 2 Sep. 2020

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

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Time Traveler for certain

Time Traveler

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

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Statistics for certain

Last Updated

20 Sep 2020

Cite this Entry

“Certain.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/certain. Accessed 21 Sep. 2020.

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More Definitions for certain


How to pronounce certain (audio)

English Language Learners Definition of certain

 (Entry 1 of 2)

: 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 say that something will definitely happen or that someone will definitely do something often followed by to + verb



English Language Learners Definition of certain (Entry 2 of 2)

formal : certain ones : particular members of a group


cer·​tain | \ ˈsər-tᵊn How to pronounce certain (audio) \

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

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