sureadjective

Thesaurus: synonyms, antonyms, and examples

certain about something
certainI feel certain that this change will be for the best.
know/say for certainI can't say for certain, but I think he's coming to the party.
sureDon't worry - I'm sure it won't be a problem.
positive"Are you sure you let the cat in?" "I'm positive."

for sure | American Dictionary

for sure

idiom(alsofor certain)
infml definitely, without a doubt:
I saw him and knew for sure that he had come to see me.