collapse vs sleepiness

collapse

verb
  • To cease to function due to a sudden breakdown; to fail suddenly and completely. 

  • To break apart and fall down suddenly; to cave in. 

  • To fold compactly. 

  • To hide additional directory (folder) levels below the selected directory (folder) levels. When a folder contains no additional folders, a minus sign (-) appears next to the folder. 

  • To pass out and fall to the floor or ground, as from exhaustion or other illness; to faint. 

  • For several batsmen to get out in quick succession 

  • To cause something to collapse. 

noun
  • Constant function, one-valued function (in automata theory) (in particular application causing a reset). 

  • The act of collapsing. 

sleepiness

noun
  • The property of being sleepy. 

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