nap vs zonk out

nap

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) 

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. 

zonk out

verb
  • To fall suddenly into a very deep sleep. 

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