ominous vs unpromising

ominous

adj
  • Specifically, giving indication of a coming ill; being an evil omen 

  • Of or pertaining to an omen or to omens; being or exhibiting an omen; significant. 

unpromising

adj
  • Not promising 

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