knock out vs retire

knock out

verb
  • To put to sleep. 

  • To fall asleep, especially suddenly. 

  • To lose the scent of hounds in fox-hunting. 

  • To eliminate from a contest or similar. 

  • To complete, especially in haste; knock off. 

  • To render unconscious, as by a blow to the head. 

  • To strike or bump (someone or something) out. 

  • To exhaust. 

  • To cause a mechanism to become non-functional by damaging or destroying it. 

  • To communicate (a message) by knocking. 

retire

verb
  • To go to bed. 

  • 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 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. 

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