aid vs assist

aid

verb
  • To provide support to; to further the progress of; to help; to assist. 

  • To climb with the use of aids such as pitons. 

noun
  • Help; assistance; succor, relief. 

  • An historical subsidy granted to the crown by Parliament for an extraordinary purpose, such as a war effort. 

  • A helper; an assistant. 

  • An exchequer loan. 

  • Something which helps; a material source of help. 

  • A pecuniary tribute paid by a vassal to his feudal lord on special occasions. 

  • The rider's use of hands, legs, voice, etc. to control the horse. 

assist

verb
  • To help. 

  • To make a pass that leads directly towards scoring. 

  • To help compensate for what is missing with the help of a medical technique or therapy. 

noun
  • A decisive pass made to the goal scorer 

  • A helpful action or an act of giving. 

  • A defensive play, allowing a teammate to record a putout. 

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