uncertain in WordNet English dictionary

1. subject to change
   "a changeable climate"; "the weather is uncertain"; "unsettled weather with rain and hail and sunshine coming one right after the other"
   changeable  uncertain  unsettled 
   
2. 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"
   uncertain  unsure  incertain 
   
3. 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"
   uncertain 
   
4. not certain to occur; not inevitable
   "everything is uncertain about the army"; "the issue is uncertain"
   uncertain 
   
5. not established or confirmed
   "his doom is as yet unsealed"
   unsealed  uncertain 
   
6. ambiguous (especially in the negative)
   "she spoke in no uncertain terms"
   uncertain 
   
7. not consistent or dependable
   "an uncertain recollection of events"; "a gun with a rather uncertain trigger"
   uncertain