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."