libel vs smear campaign

libel

noun
  • A written or pictorial false statement which unjustly seeks to damage someone's reputation. 

  • The act or tort of displaying such a statement publicly. 

  • Any defamatory writing; a lampoon; a satire. 

  • A written declaration or statement by the plaintiff of their cause of action, and of the relief they seek. 

  • A brief writing of any kind, especially a declaration, bill, certificate, request, supplication, etc. 

verb
  • To proceed against (goods, a ship, etc.) by filing a libel claim. 

  • To defame (someone), especially in a manner that meets the legal definition of libel. 

smear campaign

noun
  • An effort to damage or call into question someone's reputation, by propounding negative propaganda. 

How often have the words libel and smear campaign occurred in a corpus of books? (source: Google Ngram Viewer )