sure

/ˈʃʊər/

/ʃɔ/

Other forms: surest; surer; sures

Being sure has to do with being certain, convinced, trustworthy, or dependable. You can trust a sure thing.

Besides being a synonym for yes, sure has to do with lots of kinds of dependability. If you have a sure eye, then you have good aim, maybe with shooting a basketball or throwing darts. If you're sure of yourself, you're confident. A sure thing or sure bet is something almost certain to happen. If you're 100% convinced of something, you're sure of it.

Definitions of sure

1. adjective

   having or feeling no doubt or uncertainty; confident and assured
   “was very sure in his beliefs”

   “sure of her friends”

   synonyms: certain

   confident, convinced, positive

   persuaded of; very sure

   antonyms:

   unsure

   lacking or indicating lack of confidence or assurance

   ambivalent

   uncertain or unable to decide about what course to follow

   doubtful, dubious

   fraught with uncertainty or doubt

   groping

   acting with uncertainty or hesitance or lack of confidence
2. adjective

   certain to occur; destined or inevitable
   “sudden but sure regret”

   “he is sure to win”

   synonyms: certain

   bound, destined

   (usually followed by `to') governed by fate

   doomed, fated

   (usually followed by `to') determined by tragic fate

   foreordained, predestinate, predestined

   established or prearranged unalterably

   in for

   certain to get or have

   predictable

   capable of being foretold
3. adjective

   impossible to doubt or dispute
   synonyms: indisputable

   certain

   established beyond doubt or question; definitely known
4. adverb

   definitely or positively (`sure' is sometimes used informally for `surely')
   “he'll win sure as shooting”

   “they sure smell good”

   “sure he'll come”

   synonyms: certainly, for certain, for sure, sure as shooting, sure enough, surely
5. adjective

   reliable in operation or effect
   “a sure way to distinguish the two”

   “wood dust is a sure sign of termites”

   synonyms: certain

   dependable, reliable

   worthy of reliance or trust
6. adjective

   infallible or unfailing
   “a sure (or true) sign of one's commitment”

   synonyms:

   true

   consistent with fact or reality; not false
7. adjective

   certain not to fail
   “a sure hand on the throttle”

   synonyms:

   steady

   not subject to change or variation especially in behavior
8. adjective

   (of persons) worthy of trust or confidence
   “a sure (or trusted) friend”

   synonyms: trusted

   trustworthy, trusty

   worthy of trust or belief
9. adjective

   physically secure or dependable
   “a sure footing”

   “was on sure ground”

   synonyms:

   secure

   free from danger or risk
10. adjective

    exercising or taking care great enough to bring assurance
    “be sure to lock the doors”

    synonyms: certain

    careful

    exercising caution or showing care or attention