debigulate vs drop off

debigulate

verb
  • To reduce or shrink; to make or become smaller. 

drop off

verb
  • To lessen or reduce. 

  • To fall. 

  • To deliver; to deposit or leave; to allow passengers to alight. 

  • To fall asleep. 

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