sure 1 of 2

adjective

ˈshu̇r How to pronounce sure (audio)
Definition of surenext
1
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
2
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
3
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
4
as in true
worthy of one's trust a sister is a sure friend for life

Synonyms & Similar Words

Antonyms & Near Antonyms
5
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
The purpose of any heat shield is to be sure the extreme temperatures that objects hitting Earth’s atmosphere experience don’t harm the crew or cargo inside the vehicle. —Margaret Landis, The Conversation, 18 June 2026 Just be sure to know the accessibility restrictions with each, especially a CD account that will issue an early withdrawal penalty against savers who take their money out prematurely. —Matt Richardson, CBS News, 18 June 2026
Adverb
But sure, the president brings it up a lot, sometimes publicly, sometimes privately. —Robert Costa, CBS News, 14 June 2026 The trailer sure looks terrific! —Erik Kain, Forbes.com, 14 June 2026 See All Example Sentences for sure
Recent Examples of Synonyms for sure
  1. confident
  2. necessary
  3. reliable
  4. true
  5. conclusive
  6. definitely
  7. certain
  8. inevitable
Adjective
  • With confident goalkeeper Raúl Rangel in net, Mexico looks to shake off opening-match nerves and beat South Korea in Guadalajara.
    — Eduard Cauich, Los Angeles Times, 18 June 2026
  • So playing characters who were so ferocious and bold and confident and determined and all that helped me profoundly in my personal life.
    — Brande Victorian, HollywoodReporter, 18 June 2026
Definition of confident
Adjective
  • She's seen these parents put off their own health, including necessary surgeries.
    — Madeline Mitchell, USA Today, 20 June 2026
  • Simple, age-appropriate conversations about device use could help children understand the difference between necessary engagement and recreation.
    — Sandra Gonzalez, CNN Money, 19 June 2026
Definition of necessary
Adjective
  • The habits already known to support blood and skin health, sleep, nutrition, sun protection, not smoking and managing inflammation, remain the most reliable tools available right now.
    — Allison Palmer, Fort Worth Star-Telegram, 15 June 2026
  • Ferrari’s power unit is much more reliable, but this weekend, its hydraulics weren’t, costing Leclerc a race finish.
    — Jonathan M. Gitlin, ArsTechnica, 15 June 2026
Definition of reliable
Adjective
  • Life comes at you fast, and that could not be truer in the world of baseball.
    — Stephen J. Nesbitt, New York Times, 16 June 2026
  • This is certainly true—and a rather banal truism.
    — The Atlantic, The Atlantic, 16 June 2026
Definition of true
Adjective
  • There’s no conclusive evidence of alien life or government cover-ups.
    — ABC News, ABC News, 12 June 2026
  • However, a three-judge panel selected by the executive committee for a legal assessment of the findings found that the investigation was not conclusive enough.
    — CBS News, CBS News, 9 June 2026
Definition of conclusive
Adverb
  • Aidan Lee, 23, who is of Mexican and South Korean descent, definitely stuck out in his red South Korea jersey.
    — Clara Harter, Los Angeles Times, 19 June 2026
  • Yeah, the shape was definitely interesting—almost a new take on the low-profile sneaker, which has been sending everyone into a tizzy.
    — Christian Allaire, Vogue, 19 June 2026
Definition of definitely
Adjective
  • Ticket Holders are only permitted to bring certain types of bags into stadiums.
    — Michelle Kaufman, Miami Herald, 14 June 2026
  • Drone operations are prohibited within a 1-nautical-mile radius and up to 1,000 feet above ground level at certain fan events, including at the LA Memorial Coliseum in June, according to FAA’s news release about the restrictions.
    — Queenie Wong, Los Angeles Times, 14 June 2026
Definition of certain
Adjective
  • Labour in turmoil With Burnham’s return to front line politics, a leadership race seems all but inevitable.
    — Issy Ronald, CNN Money, 20 June 2026
  • Messi is the standing rebuttal — a leader whose authority was never announced, only demonstrated; whose visibility was never imposed, only inevitable.
    — Luis E. Romero, Forbes.com, 19 June 2026
Definition of inevitable

Phrases Containing sure

Browse Nearby Words

surd
sure
sure-enough
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Cite this Entry

“Sure.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/sure. Accessed 20 Jun. 2026.

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More from Merriam-Webster on sure

Nglish: Translation of sure for Spanish Speakers

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