retire vs sign off

retire

verb
  • To cease use or production of something. 

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

  • 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. 

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

  • A place to which one retires. 

sign off

verb
  • To cease broadcasting a radio or television signal, usually at the end of a broadcasting day. 

  • to give one's official approval to something for which it is needed 

  • To log off; to stop using a computer, radio, etc., especially to stop talking. 

noun
  • The closing of a radio or television station's studios and cessation of the broadcasting signal, usually overnight. 

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