aid vs plunge

aid

noun
  • The rider's use of hands, legs, voice, etc. to control the horse. 

  • 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. 

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

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

plunge

noun
  • The act of pitching or throwing oneself headlong or violently forward, like an unruly horse. 

  • Heavy and reckless betting in horse racing; hazardous speculation. 

  • A dive, leap, rush, or pitch into (into water). 

  • The act of plunging or submerging. 

verb
  • To pitch or throw oneself headlong or violently forward, as a horse does. 

  • To bet heavily and recklessly; to risk large sums in gambling. 

  • To thrust into liquid, or into any penetrable substance; to immerse. 

  • To cast, stab or throw into some thing, state, condition or action. 

  • To fall or rush headlong into some thing, action, state or condition. 

  • To remove a blockage by suction. 

  • To dive, leap or rush (into water or some liquid); to submerge oneself. 

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