uncertain

To be uncertain is to be unsure of something. Also, uncertain things are undecided, unknown, or doubtful in some way.

If you're certain of something, you're sure of it. When you're uncertain, you don't know. If you don't know the answer to a math question, you're uncertain. If you can't remember where you parked your car, you're uncertain about its location. Also, anything unknown or up in the air in uncertain. Trying to be a famous actor is an uncertain path. Gambling money on horses is very uncertain. And, it's certainly hard to plan for an uncertain future.

Definitions of uncertain
1

adj lacking or indicating lack of confidence or assurance

uncertain of his convictions”
“moving with uncertain (or unsure) steps”
“an uncertain smile”
“touched the ornaments with uncertain fingers”
Synonyms:
incertain, unsure
ambivalent
uncertain or unable to decide about what course to follow
doubtful, dubious
fraught with uncertainty or doubt
groping
acting with uncertainty or hesitance or lack of confidence
Antonyms:
certain, sure
having or feeling no doubt or uncertainty; confident and assured
confident, convinced, positive
persuaded of; very sure
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adj not established or confirmed

Synonyms:
unsealed
Antonyms:
certain, sealed
established irrevocably

adj ambiguous (especially in the negative)

“she spoke in no uncertain terms”
Synonyms:
ambiguous
having more than one possible meaning

adj subject to change

“the weather is uncertain
Synonyms:
changeable, unsettled
variable
liable to or capable of change

adj not consistent or dependable

“an uncertain recollection of events”
“a gun with a rather uncertain trigger”
Synonyms:
undependable, unreliable
not worthy of reliance or trust

adj 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
Synonyms:
indefinite
not decided or not known
up in the air
very uncertain
indeterminate, undetermined
not precisely determined or established; not fixed or known in advance
Antonyms:
certain
established beyond doubt or question; definitely known
definite
known for certain
indisputable, sure
impossible to doubt or dispute
sure as shooting
absolutely certain
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adj not certain to occur; not inevitable

“everything is uncertain about the army”
“the issue is uncertain
Synonyms:
chancy, flukey, fluky, iffy
subject to accident or chance or change
contingent
uncertain because of uncontrollable circumstances
up in the air
not yet determined
unpredictable
not capable of being foretold
Antonyms:
certain, sure
certain to occur; destined or inevitable
bound, destined
(usually followed by `to') governed by fate
doomed, fated
(usually followed by `to') determined by tragic fate
foreordained, predestinate, predestined
established or prearranged unalterably
in for
certain to get or have
predictable
capable of being foretold
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