advertisement vs retraction

advertisement

noun
  • A commercial solicitation designed to sell some commodity, service or similar. 

  • A public notice. 

  • In gin rummy, the discarding of a card of one's preferred suit so as to mislead the opponent into thinking you do not want it. 

  • A recommendation of a particular product, service or person. 

retraction

noun
  • A continuous function from a topological space onto a subspace which is the identity on that subspace. 

  • An act or instance of retracting. 

  • A statement printed or broadcast in a public forum which effects the withdrawal of an earlier assertion, and which concedes that the earlier assertion was in error. 

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