linkage vs separation

linkage

noun
  • A connection or relation between things or ideas. 

  • The act or result of linking: the combination of multiple object files into one executable, library, or object file. 

  • A United States foreign policy, during the 1970s détente in the Cold War, of persuading the Soviet Union to co-operate in restraining revolutions in the Third World in return for nuclear and economic concessions. 

  • A mechanical device that connects things. 

  • The property of genes of being inherited together. 

  • A set of definitely related languages for which no proto-language can be derived, typically a group of languages within a family that have formed a sprachbund. 

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 linkage and separation occurred in a corpus of books? (source: Google Ngram Viewer )