embolism vs thrombus

embolism

noun
  • An obstruction or occlusion of an artery by an embolus, that is by a blood clot, air bubble or other matter that has been transported by the blood stream. 

  • An intercalated prayer for deliverance from evil coming after the Lord's Prayer. 

  • The insertion or intercalation of days into the calendar in order to correct the error arising from the difference between the civil year and the solar year. 

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 embolism and thrombus occurred in a corpus of books? (source: Google Ngram Viewer )