besmirch

(verb) charge falsely or with malicious intent; attack the good name and reputation of someone. Synonyms: defame, slander, smirch, asperse, denigrate, calumniate, smear, sully. Example: "The journalists have defamed me!" "the article in the paper sullied my reputation."

(verb) smear so as to make dirty or stained. Synonyms: smirch.