plunge vs spiral

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. 

spiral

verb
  • To move along the path of a spiral or helix. 

  • To increase continually. 

  • To cause something to spiral. 

noun
  • A helix. 

  • A section of track that forms a circle and crosses over itself, used for gaining height in mountainous territory. 

  • A self-sustaining process with a lot of momentum involved, so it is difficult to accelerate or stop it at once. 

  • A curve that is the locus of a point that rotates about a fixed point while continuously increasing its distance from that point. 

adj
  • Helical, like a spiral. 

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