1. [Adjective]: 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 consquences"; "without further evidence his story must remain uncertain"

2. [Adjective]: not certain to occur; not inevitable; "everything is uncertain about the army"; "the issue is uncertain"

3. [Adjective]: not established or confirmed; "his doom is as yet unsealed"

4. [Adjective]: 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"

5. not consistent or dependable; "an uncertain recollection of events"; "a gun with a rather uncertain trigger"

6. not safe from danger or mishap; "faced an uncertain future"; "an unsure existence"

7. subject to change; "a changeable climate"; "the weather is uncertain"; "unsettled weather with rain and hail and sunshine coming one right after the other"

8. not firm or secure; "balancing three boxes in an uncertain pile"

9. ambiguous (especially in the negative); "she spoke in no uncertain terms"

1. ambiguous

2. indefinite

3. up_in_the_air

4. ambivalent

5. doubtful

6. dubious

7. groping

8. hesitant

9. chancy

10. fluky

11. flukey

12. iffy

13. contingent

14. up_in_the_air

15. unreliable

16. undependable

17. insecure

18. unsafe

19. insecure

20. variable

1. certain(p)

2. certain(p)

3. sure

4. certain

5. sure

6. sealed

7. certain