cumulate vs disperse

cumulate

verb
  • To be accumulated. 

  • To accumulate; to amass. 

adj
  • accumulated, agglomerated, amassed 

noun
  • An igneous rock formed by the accumulation of crystals from a magma either by settling or floating. 

disperse

verb
  • To distribute throughout. 

  • To break up and disappear; to dissipate. 

  • To scatter in different directions. 

  • To disseminate. 

  • To separate rays of light, etc., according to wavelength; to refract. 

adj
  • Scattered or spread out. 

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