infiltration vs separation

infiltration

noun
  • The act of secretly entering a physical location and/or organization. 

  • The substance which has entered the pores or cavities of a body. 

  • process by which water on the ground surface enters the soil. 

  • The act or process of infiltrating, as of water into a porous substance, or of a fluid into the cells of an organ or part of the body. 

separation

noun
  • The act of disuniting two or more things, or the condition of being separated. 

  • Departure from active duty, while not necessarily leaving the service entirely. 

  • An agreement legalizing such an arrangement. 

  • An object that separates two spaces. 

  • The act or condition of two or more people being separated from one another. 

  • The place at which a division occurs. 

  • An interval, gap or space that separates things or people. 

  • The act or condition of a married couple living in separate homes while remaining legally married. 

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