baby boy vs heartling

baby boy

noun
  • A term of endearment for a man. 

  • A very young male human being, from birth to a couple of years old. 

  • A man who is immature or infantile. 

heartling

noun
  • A term of endearment, similar to darling. 

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