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 Along with the sale of NFL Network, the NFL and ESPN will have a second nonbinding agreement where the NFL will license to ESPN certain NFL content and other intellectual property that can be used by NFL Network and other assets that have been purchased. Joe Reedy, Baltimore Sun, 6 Aug. 2025 Foods high in the amino acid tryptophan (like milk, turkey, chicken, lobster, and certain types of nuts) can also increase lethargy, according to Dr. Ganjhu. Caroline Tien, SELF, 6 Aug. 2025 Keep in mind that buckwheat can cause allergic reactions in certain people (especially in Asian countries), particularly if eaten frequently or in large amounts. Caroline Tien, SELF, 15 July 2025 However, Flow Space may receive a commission on orders placed through its retail links, and the retailer may receive certain auditable data for accounting purposes. Jessica Hartshorn, Flow Space, 14 July 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
  • Calls of three and four clubs agree diamonds, for sure.
    Deb Harvell, Arkansas Online, 17 Aug. 2025
  • But one thing is for sure — Albin’s team is ready to face an opponent who is not wearing green and white.
    Hunter Bailey, Charlotte Observer, 16 Aug. 2025
Adjective
  • Travelers are advised to consider alternative itineraries, focusing on stable routes and refundable connections, and to maintain thorough records of expenses and communication with the airline.
    Zach Wichter, USA Today, 16 Aug. 2025
  • Younger people are lonelier – many of them have trouble finding stable friendships and are unable to find a romantic partner.
    Rafael Perez, Oc Register, 16 Aug. 2025
Adjective
  • Many people in the country have a distrust of civil servants; however, civil servants with deep understanding of finance and investing are exactly the type of people who would be necessary.
    Erik Sherman, Forbes.com, 8 Aug. 2025
  • Evacuation Protocol: If evacuation becomes necessary, follow your checklist, wear protective clothing, and leave immediately.
    Amanda Castro, MSNBC Newsweek, 8 Aug. 2025
Adjective
  • Invest in acoustic privacy, reliable technology for hybrid collaboration, and layout choices that reflect different work styles.
    Gleb Tsipursky, The Orlando Sentinel, 15 Aug. 2025
  • Each day, Lamb showed up with multiple catches and proved to be the reliable target he’s been through five seasons.
    Nick Harris, Fort Worth Star-Telegram, 15 Aug. 2025
Adjective
  • Partnerships, as always, will be a definite accelerant but a high degree of critical capability should probably be insourced given the winds of change currently sweeping across the landscape of geopolitics.
    Amir Husain, Forbes.com, 15 Aug. 2025
  • Nobody 2 is prime with older guys with solid total awareness and definite interest climbing.
    Anthony D'Alessandro, Deadline, 12 Aug. 2025
Adjective
  • Willy Adames is confident the Giants could’ve turned two.
    Justice delos Santos, Mercury News, 13 Aug. 2025
  • So here’s what the data is saying: Corporations are confident—just look at buybacks.
    Frank Holmes, Forbes.com, 13 Aug. 2025
Adjective
  • Osbourne’s funeral cortege paraded past the Black Sabbath Bridge during his July 30 funeral in Birmingham, just weeks after Ozzy’s final performance at the all-star Back to the Beginning charity concert.
    Gil Kaufman, Billboard, 7 Aug. 2025
  • Edwards rarely tires of watching back footage of the feat: his electric speed down the runway, the bounding strides of his jumping action, and the enormous final vault into the sandpit.
    George Ramsay, CNN Money, 7 Aug. 2025

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Cite this Entry

“Certain.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/certain. Accessed 21 Aug. 2025.

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