What is the meaning of uncertain?

adjective

• Lacking or indicating lack of confidence or assurance.
  • usage: "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"
  • synonyms: unsure, incertain
• Not established beyond doubt; still undecided or unknown.
  • usage: "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.
  • usage: "his doom is as yet unsealed"
  • synonyms: unsealed
• Not certain to occur; not inevitable.
  • usage: "everything is uncertain about the army"; "the issue is uncertain"
• Subject to change.
  • usage: "a changeable climate"; "the weather is uncertain"; "unsettled weather with rain and hail and sunshine coming one right after the other"
  • synonyms: changeable, unsettled
• Not consistent or dependable.
  • usage: "an uncertain recollection of events"; "a gun with a rather uncertain trigger"
• Ambiguous (especially in the negative. )
  • usage: "she spoke in no uncertain terms"