1. unused

2. unclean

3. unheard

4. unkind

5. unfriendly

6. unable

7. unhappy

8. unsafe

9. uncertain

10. undecided

11. unknown

12. unlike

13. dislike

14. disagree

15. disabled

16. disobey

17. disappear

18. dishonest

19. disadvantage

20. distrust