lowering vs quelling

lowering

noun
  • The act of something being lowered. 

adj
  • Dark and menacing. 

  • Lurking, skulking, menacing. 

  • That lowers or frowns. 

quelling

noun
  • The act by which something is quelled. 

adj
  • causing something to quell or be quelled 

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