embolus vs occlusion

embolus

noun
  • An obstruction causing an embolism: a blood clot, air bubble or other matter carried by the bloodstream and causing a blockage or occlusion of a blood vessel. 

  • The structure on the end of the palp of male arachnids which contains the opening to the ejaculatory duct. 

occlusion

noun
  • The process of occluding, or something that occludes. 

  • Anything that obstructs or closes a vessel or canal. 

  • An occluded front. 

  • The absorption of a gas or liquid by a substance such as a metal. 

  • A closure within the vocal tract that produces an oral stop or nasal stop. 

  • The blocking of the view of part of an image by another. 

  • The alignment of the teeth when upper and lower jaws are brought together. 

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