harass vs retard

harass

verb
  • To put excessive burdens upon (someone); to subject (someone) to anxieties. 

  • To persistently bother (someone, or a group of people) physically or psychologically when such behaviour is illegal and/or unwanted, especially over an extended period. 

  • To annoy (someone) frequently or systematically; to pester. 

  • To trouble (someone, or a group of people) through repeated military-style attacks. 

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 harass and retard occurred in a corpus of books? (source: Google Ngram Viewer )