Definitions for unsure
Random House Webster's College Dictionary
diffident, shy, timid, unsure(adj)
"stood in the doorway diffident and abashed"; "problems that call for bold not timid responses"; "a very unsure young man"
uncertain, unsure, incertain(adj)
lacking or indicating lack of confidence or assurance
"uncertain of his convictions"; "unsure of himself and his future"; "moving with uncertain (or unsure) steps"; "an uncertain smile"; "touched the ornaments with uncertain fingers"
Kernerman English Learner's Dictionary
I'm unsure about whether to take the job.; unsure of his rights in the situation
uncertain of the facts
unstable or precarious