What is the meaning of sure?

adjective

• Having or feeling no doubt or uncertainty; confident and assured.
  • usage: "felt certain of success"; "was sure (or certain) she had seen it"; "was very sure in his beliefs"; "sure of her friends"
  • synonyms: certain
• Exercising or taking care great enough to bring assurance.
  • usage: "be certain to disconnect the iron when you are through"; "be sure to lock the doors"
  • synonyms: certain
• Certain to occur; destined or inevitable.
  • usage: "he was certain to fail"; "his fate is certain"; "In this life nothing is certain but death and taxes- Benjamin Franklin; "he faced certain death"; "sudden but sure regret"; "he is sure to win"
  • synonyms: certain
• Physically secure or dependable.
  • usage: "a sure footing"; "was on sure ground"
• Reliable in operation or effect.
  • usage: "a quick and certain remedy"; "a sure way to distinguish the two"; "wood dust is a sure sign of termites"
  • synonyms: certain
• Of persons. ( worthy of trust or confidence)
  • usage: "a sure (or trusted) friend"
  • synonyms: trusted
• Infallible or unfailing.
  • usage: "a sure (or true) sign of one's commitment"
• Certain not to fail.
  • usage: "a sure hand on the throttle"
• Impossible to doubt or dispute.
  • usage: "indisputable (or sure) proof"
  • synonyms: indisputable

adverb

• Definitely or positively (`sure' is sometimes used informally for `surely'. )
  • usage: "the results are surely encouraging"; "she certainly is a hard worker"; "it's going to be a good day for sure"; "they are coming, for certain"; "they thought he had been killed sure enough"; "he'll win sure as shooting"; "they sure smell good"; "sure he'll come"
  • synonyms: surely, certainly, for sure, for certain, sure enough, sure as shooting