abend vs leave off

abend

verb
  • To terminate abnormally. 

noun
  • The abnormal termination of a program. 

  • Termination of a process prior to completion. 

leave off

verb
  • To desist; to cease. 

  • To omit. 

  • To stop with a view to resuming at a later point. 

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