retire vs separation

retire

noun
  • The act of retiring, or the state of being retired. 

  • A place to which one retires. 

verb
  • To stop working on a permanent basis, usually because of old age or illness. 

  • To cease use or production of something. 

  • To go back or return; to withdraw or retreat, especially from public view; to go into privacy. 

  • To fit (a vehicle) with new tires. 

  • To recede; to fall or bend back. 

  • To go to bed. 

  • To withdraw; to take away. 

  • To voluntarily stop batting before being dismissed so that the next batsman can bat. 

  • To retreat from action or danger; to withdraw for safety or pleasure. 

  • To withdraw from circulation, or from the market; to take up and pay. 

  • To cause to retire; specifically, to designate as no longer qualified for active service; to place on the retired list. 

  • To make a play which results in a runner or the batter being out, either by means of a put out, fly out or strikeout. 

separation

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

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