brightness vs dusk

brightness

noun
  • Intelligence, cleverness. 

  • The quality of being bright. 

  • The perceived luminance of an object. 

dusk

adj
  • Tending to darkness or blackness; moderately dark or black; dusky. 

verb
  • To begin to lose light or whiteness; to grow dusk. 

  • To make dusk. 

noun
  • A darkish colour. 

  • The condition of being dusky; duskiness 

  • A period of time at the end of day when the sun is below the horizon but before the full onset of night, especially the darker part of twilight. 

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