bottleneck vs retard

bottleneck

verb
  • To slow by causing a bottleneck. 

  • To form a bottleneck. 

noun
  • The part of a process that is too slow or cumbersome. 

  • In traffic, any narrowing of the road, especially resulting in a delay. 

  • The narrow portion that forms the pouring spout of a bottle; the neck of a bottle. 

retard

verb
  • To decelerate; to slow down. 

  • To put off; to postpone. 

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