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 Leader says certain additives can also signal faux sourdough. Olivia McIntosh, Martha Stewart, 4 Apr. 2026 The study set strict limits on these possible effects under certain assumptions and improved models of atomic and nuclear behavior. Georgina Jedikovska, Interesting Engineering, 4 Apr. 2026 South Korea has taken advantage of a suspension of US sanctions on certain Russian oil and petroleum products to buy its first load of naphtha from Moscow since the start of the Ukraine war. Stephanie Yang, CNN Money, 4 Apr. 2026 There are also ways for early retirees to access certain retirement savings early without incurring a tax penalty. Jessica Dickler,greg Iacurci, CNBC, 4 Apr. 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
  • There’s going to be a learning curve here for people for sure.
    Joel Feder, The Drive, 2 Apr. 2026
  • The abundance of light that Koestenbaum sheds on the rabbi is humorous, sure, but also humanistic.
    Literary Hub, Literary Hub, 2 Apr. 2026
Adjective
  • Officials said Kuwait’s electricity and water systems remain stable and contingency plans had been activated to ensure continued supply, according to the statement.
    Anniek Bao, CNBC, 30 Mar. 2026
  • Officials said injury statuses ranged from stable to critical.
    Garrett Behanna, CBS News, 30 Mar. 2026
Adjective
  • Tilling is sometimes necessary, such as when incorporating compost or manure, but limiting the frequency and intensity can help maintain soil structure.
    Anthony Reardon, Kansas City Star, 4 Apr. 2026
  • And despite a battery of necessary offseason changes, everything felt the same.
    Troy Renck, Denver Post, 4 Apr. 2026
Adjective
  • Affordable yet reliable, the JBL Vibe Beam wireless earbuds are terrific for listening to your favorite tunes while commuting, hiking, exercising or at the beach.
    BestReviews, Chicago Tribune, 30 Mar. 2026
  • However, there is a reliable method for keeping crows out of your yard and letting the others live in peace.
    Joan Morris, Mercury News, 30 Mar. 2026
Adjective
  • There is a definite buzz of excitement at the press site here at the Kennedy Space Center.
    Charlie Gile, NBC news, 1 Apr. 2026
  • So far, there isn’t definite evidence of a multiverse based on string theory.
    Zachary Slepian, The Conversation, 30 Mar. 2026
Adjective
  • Gemini May 21 – June 20 The universe favors clear, confident messages.
    Tarot.com, Baltimore Sun, 3 Apr. 2026
  • May 21 – June 20 The universe favors clear, confident messages.
    Tarot.com, Sun Sentinel, 3 Apr. 2026
Adjective
  • The siting of the rites at the Colosseum—where it has been held since 1964, echoing a practice from the eighteenth century—means that the Pope enacts Jesus’ final hours not in a Baroque basilica but against the backdrop of the Roman Empire, which exercised power through violence.
    Paul Elie, New Yorker, 4 Apr. 2026
  • Ultralight pilot David Shelton filed a complaint with the FAA in October that, after back-and-forth responses with Yuba County’s attorneys, concluded with final responses in March.
    Jake Goodrick, Sacbee.com, 4 Apr. 2026

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Cite this Entry

“Certain.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/certain. Accessed 5 Apr. 2026.

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