adusk vs dusky

adusk

adj
  • Resembling conditions at dusk or twilight, low-lit, dark; in darkness, gloomy. 

adv
  • At dusk; in the dusk or twilight. 

dusky

adj
  • Dimly lit, as at dusk (evening). 

  • Ashen; having a greyish skin coloration. 

  • Having a shade of color that is rather dark. 

noun
  • A dusky dolphin. 

  • A dusky grouse. 

  • A dusky shark. 

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