cruor vs thrombus

cruor

noun
  • The clotted portion of coagulated blood, containing the colouring matter; gore. 

  • The colouring matter of the blood. 

thrombus

noun
  • A blood clot formed from platelets and other elements that forms in a blood vessel in a living organism, and causes thrombosis or obstruction of the vessel at its point of formation or travel to other areas of the body. 

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