SURE Synonyms: 230 Similar and Opposite Words

Q: How does the adjective 'sure' contrast with its synonyms?

Some common synonyms of sure are certain , cocksure , and positive . While all these words mean "having no doubt or uncertainty," sure usually stresses the subjective or intuitive feeling of assurance. // felt sure that I had forgotten something

Q: When is 'certain' a more appropriate choice than 'sure'?

In some situations, the words certain and sure are roughly equivalent. However, 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 'sure'?

The words cocksure and sure can be used in similar contexts, but cocksure implies presumptuous or careless positiveness. // you're always so cocksure about everything

Q: Where would 'positive' be a reasonable alternative to 'sure'?

The synonyms positive and sure are sometimes interchangeable, but positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it. // I'm positive that's the person I saw

sure 1 of 2

adjective

ˈshu̇r

Definition of sure

as in confident

having or showing a mind free from doubt are you absolutely sure that she said she was coming today?

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

as in necessary

impossible to avoid or evade the joke's a sure dud if you don't pause in the right places

Synonyms & Similar Words

Antonyms & Near Antonyms

as in reliable

not likely to fail a sure cure for the winter blues—a week in the Bahamas

Synonyms & Similar Words

Antonyms & Near Antonyms

as in true

worthy of one's trust a sister is a sure friend for life

Synonyms & Similar Words

Antonyms & Near Antonyms

as in conclusive

not capable of being challenged or proved wrong no sure evidence that life exists on other planets

Synonyms & Similar Words

Antonyms & Near Antonyms

sure

2 of 2

adverb

as in definitely

without any question we sure could use your help here

Synonyms & Similar Words

Synonym Chooser

How does the adjective sure contrast with its synonyms?

Some common synonyms of sure are certain, cocksure, and positive. While all these words mean "having no doubt or uncertainty," sure usually stresses the subjective or intuitive feeling of assurance.

felt sure that I had forgotten something

When is certain a more appropriate choice than sure?

In some situations, the words certain and sure are roughly equivalent. However, 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 sure?

The words cocksure and sure can be used in similar contexts, but cocksure implies presumptuous or careless positiveness.

you're always so cocksure about everything

Where would positive be a reasonable alternative to sure?

The synonyms positive and sure are sometimes interchangeable, but positive intensifies sureness or certainty and may imply opinionated conviction or forceful expression of it.

I'm positive that's the person I saw

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 sure

Adjective

D’Angelo isn’t sure how successful the school systems’ recruitment efforts will be. — Lois K. Solomon, Sun Sentinel, 8 Oct. 2026 Montgomery isn't sure where the detail came from, but another user suggested it may have been ripped from an Amazon product review. — James Peckham, PC Magazine, 8 Oct. 2026

Adverb

So these are the scheduling quirks that come with our awesome move to nine games that has sure looked so great here lately. — Mark Harris Outkick, FOXNews.com, 24 Sep. 2026 Some cold cases do eventually thaw…the result of a crisis of conscience or a dying declaration, but in the case of Shergar, sure seems like a long shot. — Jon Wertheim, CBS News, 20 Sep. 2026 See All Example Sentences for sure

Recent Examples of Synonyms for sure

Adjective

Helping someone become confident about protecting herself online can be equally valuable, particularly as more everyday tasks move online and onto apps.

— Ethan Stone October 9, Idaho Statesman, 9 Oct. 2026
The 6-foot-5, 242-pounder has learned the roles and responsibilities at defensive end, middle linebacker, weak side linebacker and strong side linebacker, and the Falcons are confident in his ability to play each at a high level.

— Daniel Flick, AJC.com, 9 Oct. 2026

Definition of confident

Adjective

Expect Raman, whom City Hall opponents have long trashed as conflict-averse, to focus on a message of possibility and positivity while holding her ground and striking back — and hard — when necessary.

— Lorraine Ali, Los Angeles Times, 14 Oct. 2026
Officials said no other evacuations were necessary and public safety employees and emergency responders remained on duty.

— Cecilio Padilla, CBS News, 13 Oct. 2026

Definition of necessary

Adjective

Democrats have circled Alaska, a typically reliable Republican state, as a winnable seat in their bid to flip the Senate in the 2026 midterm elections.

— Christian Datoc, The Washington Examiner, 14 Oct. 2026
Both problems threatened the precise control required for reliable quantum experiments.

— Aamir Khollam, Interesting Engineering, 13 Oct. 2026

Definition of reliable

Adjective

From its opening moments, Zoe Kazan’s epic, sprawling Netflix adaptation of John Steinbeck’s 1952 novel, East of Eden, announces that the monstrous Cathy Ames (played by Florence Pugh) is the true center of the story.

— Jasmine Vojdani, Vulture, 10 Oct. 2026
The true subject of the movie is the power of law, and the erosion of law.

— Owen Gleiberman, Variety, 10 Oct. 2026

Definition of true

Adjective

Some experiments also indicate improvement in markers of inflammation, though, here, as with many areas, the findings are not conclusive, says Lee.

— Will Stone, NPR, 11 Oct. 2026
The reply from John Thorn, the official historian of Major League Baseball, was far less conclusive.

— Bill Shaikin, Los Angeles Times, 6 Oct. 2026

Definition of conclusive

Adverb

Suffice it to say the mystery bullets that landed in Rate Field’s bleachers in 2023 and wounded two women definitely aren’t relevant to this feel-good story but are worth mentioning to remind us how much the Sox narrative has changed.

— Paul Sullivan, Chicago Tribune, 9 Oct. 2026
And there’s definitely times when people discover something like ‘Chestnut Man’ from the Nordics or ‘Blood of Sacrifice’ from Sweden.

— Cynthia Littleton, Variety, 9 Oct. 2026

Definition of definitely

Adjective

Los Angeles officials began discussing a ban after the city of Rialto became the first to restrict certain sales of nitrous oxide in 2017.

— Melissa Gomez, Los Angeles Times, 13 Oct. 2026
Washington’s export bans restrict their access to the best AI chips, like certain models from Nvidia and AMD, while Beijing has restricted imports of some less powerful options.

— Simone McCarthy, CNN Money, 13 Oct. 2026

Definition of certain

Adjective

In many of life’s winner-loser outcomes, the fate of the losers is all but inevitable, granted the values, resources and determination of the winners.

— James Coffin, The Orlando Sentinel, 8 Oct. 2026
With seven years having passed since the sequel’s release, a time jump had become inevitable.

— Brian Davids, HollywoodReporter, 7 Oct. 2026

Definition of inevitable

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surd

sure

sure-enough

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“Sure.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/sure. Accessed 14 Oct. 2026.

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Synonyms of sure

adjective

adverb

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