clump vs embolus

clump

noun
  • A thick group or bunch, especially of bushes or hair. 

  • A small group of trees or plants. 

  • A cluster or lump; an unshaped piece or mass. 

  • A dull thud. 

  • A thick addition to the sole of a shoe. 

  • The compressed clay of coal strata. 

verb
  • To gather in dense groups. 

  • To form clusters or lumps. 

  • To walk with heavy footfalls. 

  • To strike; to beat. 

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. 

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