Definition of "Uncertain" :
adjective: ambiguous (especially in the negative)
"She spoke in no uncertain terms."
adjective: not established beyond doubt; still undecided or unknown
"An uncertain future."
adjective: lacking or indicating lack of confidence or assurance
"Uncertain of his convictions."
adjective: not certain to occur; not inevitable
"Everything is uncertain about the army."
adjective: not consistent or dependable
"An uncertain recollection of events."
adjective: not established or confirmed
adjective: subject to change
"The weather is uncertain."