capitulate vs knuckle

capitulate

verb
  • To surrender; to end all resistance, to give up; to go along with or comply. 

knuckle

verb
  • To strike or punch. 

  • To apply pressure, or rub or massage with one's knuckles. 

  • To yield. 

  • To land on the knuckle of a curve of a slope, after a jump off a ramp that precedes the slope. 

  • To touch one's forehead as a mark of respect. 

  • To bend the fingers. 

noun
  • The rounded point where a flat changes to a slope on a piste. 

  • A cut of meat. 

  • The curved part of the cushion at the entrance to the pockets on a cue sports table. 

  • A mechanical joint. 

  • The kneejoint of a quadruped, especially of a calf; formerly used of the kneejoint of a human being. 

  • Any of the joints between the phalanges of the fingers. 

  • A contrivance, usually of brass or iron, and furnished with points, worn to protect the hand, to add force to a blow, and to disfigure the person struck; a knuckle duster. 

  • A convex portion of a vessel's figure where a sudden change of shape occurs, as in a canal boat, where a nearly vertical side joins a nearly flat bottom. 

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