ominous vs threatening

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. 

threatening

adj
  • Making threats, making statements about a willingness to cause harm. 

  • Presenting a threat, posing a likely risk of harm. 

noun
  • An act of threatening; a threat. 

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