aid vs ward off

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. 

ward off

verb
  • To avert or prevent. 

  • To parry, or turn aside. 

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