Something uncertain.
"The future of the project remains uncertain."
not established beyond doubt; still undecided or unknown
"an uncertain future"
"a manuscript of uncertain origin"
"plans are still uncertain"
"changes of great if uncertain consequences"
"without further evidence his story must remain uncertain"
not certain to occur; not inevitable
"everything is uncertain about the army"
"the issue is uncertain"
subject to change
"a changeable climate"
"the weather is uncertain"
"unsettled weather with rain and hail and sunshine coming one right after the other"
not consistent or dependable
"an uncertain recollection of events"
"a gun with a rather uncertain trigger"
Not certain; unsure.
"She looked uncertain as she waited to hear her interview results."
The word uncertain comes from Middle English and was formed by adding the prefix un- to the word certain. It entered English with its current meaning of not being sure or definite.