asphyxiation vs smotheration

asphyxiation

noun
  • An acute lack of oxygen. 

  • Death due to lack of oxygen. 

smotheration

noun
  • Suffocation. 

  • A sailors' dish of meat buried in potatoes. 

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