circulation vs dispersal

circulation

noun
  • The extent to which anything circulates or is circulated; the measurement of diffusion 

  • The act of passing from place to place or person to person; free diffusion; transmission. 

  • Currency; circulating coins; notes, bills, etc., current for coin. 

  • The movement of the sap in the vessels and tissues of plants. 

  • The act of moving in a circle, or in a course which brings the moving body to the place where its motion began. 

  • The movement of the blood in the circulatory system, by which it is brought into close relations with the cells and tissues of the body; (loosely) the circulatory system. 

dispersal

noun
  • The act or result of dispersing or scattering; dispersion. 

  • A dispersal prison. 

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