Verbs

(v)minimize, belittle, denigrate, derogatecause to seem less serious; play down“Don't belittle his influence”
(v)defame, slander, smirch, asperse, denigrate, calumniate, smear, sully, besmirchcharge falsely or with malicious intent; attack the good name and reputation of someone“The journalists have defamed me!”, “The article in the paper sullied my reputation”