Defamation

(n.) Act of injuring another's reputation by any slanderous communication, written or oral; as, defamation of character; the wrong of maliciously injuring the good name of another; slander; detraction; calumny; aspersion.

Thesaurus Entries

attack, backbiting, backstabbing, belittlement, blackening, calumny, character assassination, defamation of character, defilement, denigration, depreciation, disparagement, malicious defamation, muckraking, mudslinging, name-calling, revilement, scandal, slander, smear, smear campaign, smear word, tale, vilification