noun. The act of calumniating; calumny.

noun. False accusation of crime or offense, or a malicious and false representation of the words or actions of another, with a view to injure his good name.

noun. A false accusation, or a malicious statement, about someone.

noun. a false accusation of an offense or a malicious misrepresentation of someone's words or actions

"If we're going by just "overrated" not all the way to "terribly disappointing" I'd like to nominate Lolita, as, even though it's a calumniation of many Nabikov obsessions, it is certainly not his best."

depreciation  derogation  disparagement  

assassination  blackwash  character assassination  epithet  libel  

canonicalization  counterfeiting  extenuation  half-impatient  impenitency