aid vs promotion

aid

noun
  • A helper; an assistant. 

  • Help; assistance; succor, relief. 

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

  • 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. 

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

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

promotion

noun
  • An advancement in rank or position. 

  • An event intended to increase the reach or image of a product or brand. 

  • Transformation of a pawn into a piece (by reaching the opponent's back rank). 

  • Dissemination of information in order to increase its popularity. 

  • Forward motion. (Contrast remotion.) 

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