desuetude vs ending

desuetude

noun
  • The state when something (for example, a custom or a law) is no longer observed nor practised; disuse, obsolescence; (countable) an instance of this. 

ending

noun
  • A termination or conclusion. 

  • The last part of something. 

  • The last morpheme of a word, added to some base to make an inflected form (such as -s in "dogs"). 

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