aid vs substantial

aid

noun
  • Something which helps; a material source of help. 

  • 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. 

  • 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. 

substantial

noun
  • Anything having substance; an essential part. 

adj
  • Most important; essential. 

  • Not imaginary; real; actual; true; veritable. 

  • Having a substance; actually existing. 

  • Corporeal; material; firm. 

  • Possessed of goods or an estate; moderately wealthy. 

  • Satisfying; having sufficient substance to be nourishing or filling. 

  • Large in size, quantity, or value; ample; significant. 

  • Having good substance; strong; stout; solid; firm. 

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