congestion vs inspissation

congestion

noun
  • An accumulation or buildup, the act of gathering into a heap or mass. 

  • An excess of mucus or fluid in the respiratory system; congestion of the lungs, or nasal congestion. 

  • An excess of traffic; usually not a complete standstill of traffic, so usually not synonymous with traffic jam. 

  • edema, water retention, swelling, enlargement of a body part because of fluid retention in tissues and vessels 

  • Blocking up of the capillary and other blood vessels, etc., in any locality or organ (often producing other morbid symptoms); local hypermic, active or passive 

inspissation

noun
  • The act of thickening. The process by which something is inspissated. 

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