quelling vs waning

quelling

noun
  • The act by which something is quelled. 

adj
  • causing something to quell or be quelled 

waning

noun
  • The fact or act of becoming less or less intense or present; fading. 

  • The fact or act of becoming smaller. 

adj
  • Becoming weaker or smaller. 

  • Of the lunar phase: as it shrinks when viewed from the Earth. 

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