pass on vs retard

pass on

verb
  • To skip or decline. 

  • To convey or communicate. 

  • To go forward. 

  • To die. 

  • To transfer (something) to someone, especially by handing or bequeathing it to the next person in a series. 

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