onomastics vs pronunciation

onomastics

noun
  • The branch of lexicology devoted to the study of names and naming, especially the origins of names. 

pronunciation

noun
  • The act of pronouncing or uttering a vocable. 

  • The formal or informal way in which a word is made to sound when spoken. 

  • The way in which the words of a language are made to sound when speaking. 

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