CERTAIN Synonyms: 186 Similar and Opposite Words

Q: 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

Q: 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

Q: 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

Q: 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

certain

adjective

ˈsər-tᵊn

Definition of certain next

as in one

known but not named a certain person told me that today is your birthday

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

as in sure

having or showing a mind free from doubt I'm certain that they'll arrive on time

Synonyms & Similar Words

Antonyms & Near Antonyms

as in stable

having been established and usually not subject to change a certain percentage of the profits will go to charity

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Antonyms & Near Antonyms

as in necessary

impossible to avoid or evade as he got older, the athlete began to feel the certain effects of the aging process on his body

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Antonyms & Near Antonyms

as in reliable

not likely to fail chicken soup is grandma's certain cure for pretty much whatever ails you

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Antonyms & Near Antonyms

as in definite

not capable of being challenged or proved wrong up to this point there's been no certain evidence that a crime has been committed

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Antonyms & Near Antonyms

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 Similarly, certain activities in the brain, such as stress, can directly affect the gut, causing digestive symptoms and imbalances in the gut microbiome.7 The gut and brain communicate through the enteric nervous system via the gut-brain connection. —

Brittany Dube, Health, 8 Feb. 2025 There are reasons to like certain Eagles matchups, like their excellent secondary against the Chiefs receivers or tailback Saquon Barkley against a KC defense that struggled to stop the run in the AFC Championship against the Buffalo Bills. —

Jesse Newell, Kansas City Star, 8 Feb. 2025 In nature, bioluminescence refers to certain organisms like jellyfish, fireflies and plankton, which can emit a glowing light. —

Perri Ormont Blumberg Fox News, Fox News, 8 Feb. 2025 Troye Sivan feels the rush for certain things in the LGBTQ+ community. —

Brian Anthony Hernandez, People.com, 8 Feb. 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