Definition of "Sure" :
adjective: exercising or taking care great enough to bring assurance
"Be sure to lock the doors."
adjective: impossible to doubt or dispute
"Indisputable (or sure) proof."
adjective: having or feeling no doubt or uncertainty; confident and assured
"Was sure (or certain) she had seen it."
adjective: certain to occur; destined or inevitable
"Sudden but sure regret."
adjective: reliable in operation or effect
"A sure way to distinguish the two."
adjective: physically secure or dependable
"A sure footing."
adjective: certain not to fail
"A sure hand on the throttle."
adjective: infallible or unfailing
"A sure (or true) sign of one's commitment."
adjective: (of persons) worthy of trust or confidence
"A sure (or trusted) friend."
adverb: definitely or positively (sure' is sometimes used informally for surely')
"The results are surely encouraging."