hebetate vs obtund

hebetate

verb
  • To render obtuse; to dull; to blunt. 

adj
  • obtuse; dull 

  • Having a dull or blunt and soft point 

obtund

verb
  • To reduce the edge or effects of; to mitigate; to dull. 

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