hazy vs unascertainable

hazy

adj
  • Obscure; confused; not clear. 

  • Thick or obscured with haze. 

  • Not clear or transparent. 

unascertainable

adj
  • That cannot be ascertained; uncertain, unable to be determined or discovered. 

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