uncertain

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”

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 established or confirmed

• “his doom is as yet unsealed”

not firm or secure

• “balancing three boxes in an uncertain pile”

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 safe from danger or mishap

• “faced an uncertain future”
• “an unsure existence”

not consistent or dependable

• “an uncertain recollection of events”
• “a gun with a rather uncertain trigger”

ambiguous (especially in the negative)

• “she spoke in no uncertain terms”