hebetate vs leaden

hebetate

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

adj
  • obtuse; dull 

  • Having a dull or blunt and soft point 

leaden

verb
  • To make or become dull or overcast. 

adj
  • Dull; darkened with overcast. 

  • Pertaining to or resembling lead; grey, heavy, sluggish. 

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