Noun
1. defamation
2. defamation of character
3. character assassination
4. calumny
9. vilification
12. insult
13. slander
14. malicious gossip
15. lie
16. slur
17. smear
18. untruth
19. false report
21. bad-mouthing
Verb
22. defame
23. malign
24. slander
25. blacken someone's name
28. traduce
29. smear
30. cast aspersions on
32. besmirch
33. tarnish
34. taint
35. tell lies about
36. stain
38. vilify
39. denigrate
40. disparage
42. stigmatize
43. discredit
44. slur
45. dis
46. bad-mouth
47. derogate
48. calumniate