adusk vs pitch-black

adusk

adj

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

adv

  • At dusk; in the dusk or twilight. 

pitch-black

adj

  • Very dark; without light. 

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