accelerate vs retard

accelerate

verb
  • To hasten, as the occurrence of an event. 

  • To become faster; to begin to move more quickly. 

  • To enable a student to finish a course of study in less than normal time. 

  • Grow; increase. 

  • To quicken the natural or ordinary progression or process of. 

  • To cause to move faster; to quicken the motion of; to add to the speed of. 

  • To cause a change of velocity. 

adj
  • Accelerated; quickened; hastened; hurried. 

retard

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

  • To put off; to postpone. 

  • To decelerate; to slow down. 

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