sure in WordNet English dictionary

1. having or feeling no doubt or uncertainty; confident and assured
   "felt certain of success"; "was sure (or certain) she had seen it"; "was very sure in his beliefs"; "sure of her friends"
   certain  sure 
   
2. certain to occur; destined or inevitable
   "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"
   certain  sure 
   
3. exercising or taking care great enough to bring assurance
   "be certain to disconnect the iron when you are through"; "be sure to lock the doors"
   certain  sure 
   
4. reliable in operation or effect
   "a quick and certain remedy"; "a sure way to distinguish the two"; "wood dust is a sure sign of termites"
   certain  sure 
   
5. impossible to doubt or dispute
   "indisputable (or sure) proof"
   indisputable  sure 
   
6. physically secure or dependable
   "a sure footing"; "was on sure ground"
   sure 
   
7. certain not to fail
   "a sure hand on the throttle"
   sure 
   
8. infallible or unfailing
   "a sure (or true) sign of one's commitment"
   sure 
   
9. (of persons) worthy of trust or confidence
   "a sure (or trusted) friend"
   sure  trusted 
   

1. definitely or positively (`sure' is sometimes used informally for `surely')
   "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"
   surely  certainly  sure  for sure  for certain  sure enough  sure as shooting  surely  certainly  sure  for sure  for certain  sure enough  sure as shooting