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 The bill would mandate prison terms of up to five years for someone entering or reentering the country illegally and stiffer penalties for those who commit certain crimes. David Lightman, Sacbee.com, 26 Sep. 2025 In 2025, China imposed export restrictions on certain rare earths and magnets as part of broader trade measures. Kaif Shaikh, Interesting Engineering, 26 Sep. 2025 Accordingly, the film retains certain elements of the novel, but omits or changes others. Andrew McGowan, Variety, 26 Sep. 2025 The paint itself, in certain cases, is very thick. Katie Abel, Footwear News, 26 Sep. 2025 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
  • Her sister wasn’t sure if her parents ever filed a missing person’s report, but said the family had no idea where to look for her.
    Saleen Martin, USA Today, 22 Sep. 2025
  • Harris is still not sure how to do that.
    David Weigel, semafor.com, 22 Sep. 2025
Adjective
  • One of the beneficiaries of this movement was Europe , where investors saw a stable but undervalued market.
    Chloe Taylor, CNBC, 24 Sep. 2025
  • Cruz confirmed one victim was transported to the hospital in critical condition, another in stable condition, and the third had minor injuries.
    Doc Louallen, ABC News, 24 Sep. 2025
Adjective
  • To help prolong the life of your heavy-duty bedding, only wash when necessary, and consider using a duvet to reduce the frequency of cleaning.
    Patricia Shannon, Southern Living, 28 Sep. 2025
  • The deal is good at any participating Krispy Kreme shop for a free medium hot or iced coffee and a free doughnut of choice, no purchase necessary (good in stores and via drive-thru at participating shops).
    Mike Snider, USA Today, 28 Sep. 2025
Adjective
  • After all, calculators are more reliable than mental math.
    Alexis Kayser, MSNBC Newsweek, 24 Sep. 2025
  • One route there, of course, is more reliable minutes with offensively gifted players.
    The Athletic NHL, New York Times, 24 Sep. 2025
Adjective
  • But that might not give you a definite idea of how the drink may affect you.
    Amy Brightfield, Better Homes & Gardens, 23 Sep. 2025
  • Both are definite building blocks moving forward for the organization.
    Robert Marvi, MSNBC Newsweek, 18 Sep. 2025
Adjective
  • His return to the company, this time with a new, more confident persona, is the culmination of a long and unique journey.
    Andrew Ravens‎, MSNBC Newsweek, 24 Sep. 2025
  • The actor was photographed out and about in New York in a pair of low-rise, super light wash blue baggy jeans that featured one confident rip on the knee.
    Anna Cafolla, Vogue, 24 Sep. 2025
Adjective
  • Hurray for the Riff Raff is supporting the Head and The Heart on the final few dates of their in-progress North American headlining tour.
    Arkansas Online, Arkansas Online, 28 Sep. 2025
  • Though he was outdueled by Aaron Nola, whose bid for perfection was broken up by Christian Vázquez’s solo home run with two outs in the sixth inning, Ryan turned in one final strong start to cap the best season of his career.
    Betsy Helfand, Twin Cities, 27 Sep. 2025

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Cite this Entry

“Certain.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/certain. Accessed 29 Sep. 2025.

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