Definition of certainnext
1
as in one
known but not named a certain person told me that today is your birthday

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

2
3
4
5
as in reliable
not likely to fail chicken soup is grandma's certain cure for pretty much whatever ails you

Synonyms & Similar Words

Antonyms & Near Antonyms

6

Synonym Chooser

How does the adjective certain contrast with its synonyms?

Some common synonyms of certain are cocksure, positive, and sure. While all these words mean "having no doubt or uncertainty," 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

When would cocksure be a good substitute for certain?

In some situations, the words cocksure and certain are roughly equivalent. However, cocksure implies presumptuous or careless positiveness.

you're always so cocksure about everything

When is it sensible to use positive instead of certain?

While the synonyms positive and certain are close in meaning, positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it.

I'm positive that's the person I saw

When could sure be used to replace certain?

The words sure and certain are synonyms, but do differ in nuance. Specifically, sure usually stresses the subjective or intuitive feeling of assurance.

felt sure that I had forgotten something

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of certain While prices for certain imports like beef, coffee and tomatoes increased significantly last year, price hikes overall were little changed. Elisabeth Buchwald, CNN Money, 10 Jan. 2026 Because of this rare condition, superstitions and myths have permeated certain African countries, both positive and negative. Destiny Jackson, Deadline, 10 Jan. 2026 Some cruise lines also restrict certain areas of their ships to adults. Deirdre Bardolf, FOXNews.com, 10 Jan. 2026 Smith said that the increase in disaster costs is driven by greater exposure and vulnerability to extreme events, as well as by certain hazard types becoming more frequent or intense due to the influence of climate change. Doyle Rice, USA Today, 10 Jan. 2026 See All Example Sentences for certain
Recent Examples of Synonyms for certain
Adjective
  • Drinkwater didn't make one appearance in a Chelsea shirt last season, whilst Bakayoko spent the season in Italy on loan at AC Milan.
    SI.com, SI.com, 3 Aug. 2019
  • Decisions made by engineers today, in other words, will determine not how one car drives but how all cars drive.
    Johannes Himmelreich, BostonGlobe.com, 30 Mar. 2018
Adjective
  • These manuals scratch the nostalgia itch, sure, but also exemplify a greater desire for offline, focused activities that can serve as a salve for our dwindling attention spans.
    Kristina Rodulfo, Vogue, 15 Jan. 2026
  • The puck was mostly in Buffalo’s end, the Sabres were held without a shot for the first nine minutes and 20 seconds of the game, and Nikita Grebenkin was robbed of what looked like a sure goal by Ukko-Pekka Luukkonen after a slick backhand feed from Owen Tippett.
    Kevin Kurz, New York Times, 15 Jan. 2026
Adjective
  • Polk said the astronaut is stable but that diagnostic uncertainty in microgravity prompted NASA to err on the side of bringing the crew member back to Earth.
    Greg Wehner, FOXNews.com, 9 Jan. 2026
  • Treaties assume shared values, stable circumstances, and mutual benefit.
    Daniel Ross Goodman, The Washington Examiner, 9 Jan. 2026
Adjective
  • The moratorium, which was confirmed by the league, was necessary because the sides failed to reach a deal on a new collective bargaining agreement or an extension of the current one by Friday night’s deadline.
    Doug Feinberg, Twin Cities, 13 Jan. 2026
  • The moratorium, which was confirmed by the league, was necessary because the sides failed to reach a deal on a new collective bargaining agreement or an extension of the current one by Friday night's deadline.
    Arkansas Online, Arkansas Online, 13 Jan. 2026
Adjective
  • For decades, Venezuela was one of America's closest partners in Latin America, a reliable energy supplier, and a democracy that helped anchor the region.
    Arkansas Online, Arkansas Online, 9 Jan. 2026
  • Finding the right toiletry bag for your next trip is as important as buying a reliable carry-on or a hassle-free backpack.
    Michelle Baricevic, Travel + Leisure, 9 Jan. 2026
Adjective
  • The palace hasn't clarified when the former Prince Andrew, now called Andrew Mountbatten-Windsor, will officially move out of Royal Lodge or whether Marsh Farm is his definite destination.
    Janine Henni, PEOPLE, 14 Jan. 2026
  • There’s no Rotten Tomatoes critics score on Bone Temple yet, but the last 28 Years Later did 89% with critics, 63% with audiences, a B CinemaScore and an OK 52% definite recommend on Screen Engine/Comscore’s PostTrak, with a big turnout by men over 25 at 49% followed by 26% women over 25.
    Anthony D'Alessandro, Deadline, 13 Jan. 2026
Adjective
  • Boyce is confident that as the season progresses and more results are in the computer, and as more teams get it together and report all of their results, the accuracy of the rankings will improve.
    Steve Fryer, Oc Register, 16 Jan. 2026
  • Lost Lambs is a confident if uneven start for a morbidly funny writer.
    Literary Hub, Literary Hub, 15 Jan. 2026
Adjective
  • With Packers first-year team president Ed Policy likely approaching a decision on LaFleur’s future this offseason before the final year of his contract, LaFleur did himself no favors ahead of those conversations.
    The Athletic NFL Staff, New York Times, 12 Jan. 2026
  • Jordan Strauss/Invision/AP George Clooney and Don Cheadle, who came onstage to present the final award for the night, joked about the standing ovation, with Cheadle noting Clooney did not receive one.
    Aliza Chasan, CBS News, 12 Jan. 2026

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Cite this Entry

“Certain.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/certain. Accessed 21 Jan. 2026.

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