nap vs rollover

nap

noun
  • A card game in which players take tricks; properly Napoleon. 

  • A soft or fuzzy surface, generally on fabric or leather. 

  • A cup, bowl. 

  • A bid to take five tricks in the card game Napoleon. 

  • The common direction, on some kinds of fabric, of the hairs making up the pile. 

  • A short period of sleep, especially one during the day. 

  • A type of bet in British horse racing, based on the experts' best tips. 

verb
  • To have a nap; to sleep for a short period of time, especially during the day. 

  • To form or raise a soft or fuzzy surface on (fabric or leather). 

  • To be off one's guard. 

  • To cover (something) with a sauce. (usually in the passive) 

rollover

noun
  • A target on the pinball table that is activated when the ball rolls over it. 

  • A graphic element that changes its appearance when the cursor moves over it. 

  • A road traffic accident in which a vehicle overturns. 

  • In the National or European lottery, the situation in which a jackpot that has not been won is carried over to the next week. 

  • The reinvestment of funds in a new issue of the same or similar investment. 

  • The process of incrementing, especially back to an initial value. 

  • A keyboard feature where each key is scanned independently, so that multiple simultaneous keypresses always register correctly. 

  • A fee paid by a borrower in order to defer full repayment of a loan. 

  • The sudden ignition of flammable gasses (produced by pyrolysis in an oxygen-poor environment) near the ceiling of a room or other enclosed space. 

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