aid vs be someone's knight in shining armor

aid

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

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

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. 

be someone's knight in shining armor

How often have the words aid and be someone's knight in shining armor occurred in a corpus of books? (source: Google Ngram Viewer )