plunge vs unhorse

plunge

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

  • 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 remove a blockage by suction. 

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

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

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

  • The act of plunging or submerging. 

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

unhorse

verb
  • To disrupt or unseat; to remove from a position. 

  • To forcibly remove from a horse. 

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