sure

[ shoor, shur ]

adjective

, sur·er, sur·est.

1. free from doubt as to the reliability, character, action, etc., of something:

   to be sure of one's data.

2. confident, as of something expected:

   sure of success.

3. convinced, fully persuaded, or positive:

   to be sure of a person's guilt.

4. assured or certain beyond question:

   a sure victory.

5. worthy of confidence; reliable; stable:

   a sure messenger.

6. unfailing; never disappointing expectations:

   a sure cure.

7. unerring; never missing, slipping, etc.:

   a sure aim.

8. admitting of no doubt or question:

   sure proof.

9. destined; bound inevitably; certain:

   sure death.

10. Obsolete. secure; safe.
11. be sure, to take care (to be or do as specified); be certain:

    Be sure to close the windows.

adverb

1. Informal. certainly; surely:

   It sure is cold out. Sure, I'll come.

sure

/ ʃɔː; ʃʊə /

adjective

1. sometimes foll by of free from hesitancy or uncertainty (with regard to a belief, conviction, etc)

   I am sure that he is lying

   we are sure of the accuracy of the data

2. foll by of having no doubt, as of the occurrence of a future state or event

   sure of success

3. always effective; unfailing

   a sure remedy

4. reliable in indication or accuracy

   a sure criterion

5. (of persons) worthy of trust or confidence

   a sure friend

6. not open to doubt

   sure proof

7. admitting of no vacillation or doubt

   he is very sure in his beliefs

8. bound to be or occur; inevitable

   victory is sure

9. postpositive bound inevitably (to be or do something); certain

   she is sure to be there tonight

10. physically secure or dependable

    a sure footing

11. obsolete.
    free from exposure to harm or danger
12. be sure
    usually imperative or dependent imperative; takes a clause as object or an infinitive, sometimes with to replaced by and to be careful or certain

    be sure and shut the door

    I told him to be sure to shut the door

13. for sure
    without a doubt; surely
14. make sure
    1. takes a clause as object to make certain; ensure
    2. foll by of to establish or confirm power or possession (over)
15. sure enough informal.
    as might have been confidently expected; definitely: often used as a sentence substitute
16. to be sure
    1. without doubt; certainly
    2. it has to be acknowledged; admittedly

adverb

1. informal.
   sentence substitute willingly; yes
2. informal.
   sentence modifier without question; certainly

Confusables Note

Both sure and surely are used as intensifying adverbs with the sense “undoubtedly, certainly.” In this use, sure is generally informal and occurs mainly in speech and written representations of speech: She sure dazzled the audience with her acceptance speech. It was sure hot enough in the auditorium. Surely is used in this sense in all varieties of speech and writing, even the most formal: The court ruled that the law was surely meant to apply to both profit-making and nonprofit organizations. quick, slow.

Derived Forms

• ˈsureness, noun

Other Words From

• sureness noun
• over·sure adjective
• over·surely adverb
• over·sureness noun
• un·sure adjective
• un·surely adverb
• un·sureness noun

Word History and Origins

Origin of sure¹

First recorded in 1300–50; Middle English sur(e), from Middle French sur, Old French seur, from Latin sēcūrus “carefree”; secure

Word History and Origins

Origin of sure¹

C14: from Old French seur, from Latin sēcūrus secure

Idioms and Phrases

Idioms

1. for sure, as a certainty; surely:

   It's going to be a good day, for sure.

2. make sure, to be or become absolutely certain:

   I'm calling to make sure that you remember to come.

3. sure enough, Informal. as might have been supposed; actually; certainly:

   Sure enough, the picnic was rained out.

4. to be sure,
   1. without doubt; surely; certainly.
   2. admittedly:

      She sings well, to be sure, but she can't act.

More idioms and phrases containing sure

• for certain (sure)
• make sure
• slow but sure
• to be sure

Example Sentences

He recalled that his mother made sure to keep him from getting a big head, asking people on the “Family Matters” set to keep constant tabs on him.

From Los Angeles Times

Let’s do what we can to put guardrails in place, where her greatness and her popularity can soar, but making sure we always have her safety in mind.

From Los Angeles Times

While confirming DR Congo had turned a corner, he warned it was too soon to be sure the outbreak was over.

From BBC

Make sure to set a reminder to check on the form.

From Salon

In an article published Friday in Paris, where he now lives, Daoud expressed concern for his “friend” Sansal, who he was sure had been arrested.

From BBC

Related Words

• assured
• certain
• confident
• decisive
• positive

When To Use

What are other ways to say sure?

Someone who is sure of something is free from doubt about its reliability or character. How does sure compare to synonyms certain, confident, or positive? Learn more on Thesaurus.com.