aid vs protect

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. 

protect

verb
  • To keep safe; to defend; to guard; to prevent harm coming to. 

  • To book a passenger on a later flight if there is a chance they will not be able to board their earlier reserved flight. 

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