Definitions
1.adjectivePhysically secure and certain, non-failing, reliable."This investment is a sure thing. The bailiff had a sure grip on the prisoner's arm."
2.adjectiveCertain in one's knowledge or belief."He was sure she was lying. I am sure of my eventual death. John was acting sure of himself but in truth had doubts."
3.adjectiveCertain to act or be a specified way."Be sure to lock the door when you leave."
4.adjectiveFree from danger; safe; secure.
5.adjectiveBetrothed; engaged to marry.
6.adverb(modal adverb) Without doubt, certainly.""Did you kill that bear yourself?" ―"I sure did!""
7.interjectionYes. (Expresses noncommittal agreement or consent.)""Do you want me to put this in the garage?" "Sure, go ahead.""
8.interjectionYes; of course.""Could you tell me where the washrooms are?" "Sure, they're in the corner over there.""