hypocorism vs hypocoristic

hypocorism

noun
  • The formation of terms of endearment or pet names. 

  • Baby talk, such as bow-wow for dog and choo-choo for train. 

  • A term of endearment; a hypocoristic, a pet name. 

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. 

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