hypocoristic vs pseudonym

hypocoristic

noun
  • A nickname, especially one indicating intimacy and formed through a shortening of the original name. 

adj
  • Relating to a nickname, usually indicating intimacy with the person. 

  • Relating to baby talk. 

pseudonym

noun
  • A fictitious name (more literally, a false name), as those used by writers and movie stars. 

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