digging vs plunge

digging

noun
  • The action performed by a person or thing that digs. 

  • A place where ore is dug, especially certain localities in California, Australia, etc. where gold is obtained. 

plunge

noun
  • The act of plunging or submerging. 

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

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

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

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 digging and plunge occurred in a corpus of books? (source: Google Ngram Viewer )