obnubilate vs sheathe

obnubilate

verb
  • To make cloudy. 

sheathe

verb
  • To thrust (a sharp object like a sword, a claw, or a tusk) into something. 

  • To put (something such as a knife or sword) into a sheath. 

  • Of an animal: to draw back or retract (a body part) into the body, such as claws into a paw. 

  • To encase (something) with a protective covering. 

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