epithet vs motto

epithet

noun
  • A term used to characterize a person or thing. 

  • A word in the scientific name of a taxon following the name of the genus or species. This applies only to formal names of plants, fungi and bacteria. In formal names of animals the corresponding term is the specific name. 

  • A term used as a qualifier of the name of a deity in order to designate said deity in a particular aspect or role. 

  • One of many formulaic words or phrases used in the Iliad and Odyssey to characterize a person, a group of people, or a thing. 

  • A term used as a descriptive substitute for the name or title of a person. 

  • An abusive or contemptuous word or phrase. 

verb
  • To term; to refer to as. 

motto

noun
  • A sentence, phrase, or word, forming part of an heraldic achievement. 

  • A sentence, phrase, or word, prefixed to an essay, discourse, chapter, canto, or the like, suggestive of its subject matter; a short, suggestive expression of a guiding principle; a maxim. 

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