Verb
1. reject
2. refuse
3. dismiss
4. say no to
5. ban
6. bar
7. block
8. debar
9. forbid
10. prohibit
11. cancel
12. invalidate
13. overrule
14. quash
15. overturn
16. countermand
17. reverse
19. set aside
20. give the thumbs down to
21. veto
22. nix