Synonyms & Antonyms of sure

(Entry 1 of 2)

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

Synonyms for sure

Words Related to sure

Near Antonyms for sure

Antonyms for sure

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

Synonyms for sure

Words Related to sure

Phrases Synonymous with sure

Near Antonyms for sure

Antonyms for sure

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

Synonyms for sure

Words Related to sure

Near Antonyms for sure

Antonyms for sure



Synonyms of sure (Entry 2 of 2)

See the Dictionary Definition 

Frequently Asked Questions About sure

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

Keep scrolling for more

Learn More about sure

Time Traveler for sure

Time Traveler

The first known use of sure was in the 13th century

See more words from the same century

Cite this Entry

“Sure.” Thesaurus, Merriam-Webster, Accessed 5 Mar. 2021.

Style: MLA
MLA Chicago APA Merriam-Webster

Keep scrolling for more

More from Merriam-Webster on sure

Dictionary: Definition of sure

Nglish: Translation of sure for Spanish Speakers

Britannica English: Translation of sure for Arabic Speakers

Comments on sure

What made you want to look up sure? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Who Knew?

Spell It

Can you spell these 10 commonly misspelled words?

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!