Verb
1. repeal
2. revoke
3. rescind
4. repudiate
5. overturn
6. annul
7. disallow
8. cancel
9. invalidate
10. nullify
11. void
12. negate
13. dissolve
14. countermand
15. declare null and void
16. discontinue
17. reverse
18. retract
19. remove
20. withdraw
21. abolish
22. put an end to
23. do away with
24. get rid of
25. end
26. stop
27. quash
28. scrap
29. disaffirm