byword vs lexeme

byword

noun
  • A characteristic word or expression; a word or phrase associated with a person or group. 

  • A nickname or epithet. 

  • Someone or something that stands as an example (i.e. metonymically) for something else, by having some of that something's characteristic traits. 

  • A proverb or proverbial expression, common saying; a frequently used word or phrase. 

  • An object of notoriety or contempt, scorn or derision. 

lexeme

noun
  • The word-form chosen to represent such a set or family. 

  • The set itself; a lexemic family. 

  • The abstract minimum unit of language or meaning that underlies such a set. 

  • An individual instance of a continuous character sequence without spaces, used in lexical analysis (see token). 

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