aid vs favor

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. 

favor

verb
  • To encourage, conduce to 

  • To resemble; especially, to look like (another person). 

  • To do a favor [noun sense 1] for; to show beneficence toward. 

  • To look upon fondly; to prefer. 

  • To use more often. 

  • To treat with care. 

noun
  • A small gift; a party favor. 

  • Mildness or mitigation of punishment; lenity. 

  • A kind or helpful deed; an instance of voluntarily assisting (someone). 

  • Partiality; bias 

  • Goodwill; benevolent regard. 

  • The object of regard; person or thing favoured. 

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