activate vs retard

activate

verb
  • To put a device, mechanism (alarm etc.) or system into action or motion; to trigger, to actuate, to set off, to enable. 

  • To organize or create a military unit or station. 

  • To bring a player back after an injury. 

  • To render a substance radioactive. 

  • To hasten a chemical reaction, especially by heating. 

  • To render more reactive; excite. 

  • To remove the limitations of demoware by providing a license; to unlock. 

  • To render a molecule reactive, active, or effective in performing its function. 

  • To encourage development or induce increased activity; to stimulate. 

  • To aerate in order to aid decomposition of organic matter. 

retard

verb
  • To put off; to postpone. 

  • To decelerate; to slow down. 

  • To keep delaying; to continue to hinder; to prevent from progressing. 

noun
  • Retardation; delay. 

  • A slowing down of the tempo; a ritardando. 

  • A person or being who is extremely stupid or slow to learn. 

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