belt-tightening vs waning

belt-tightening

adj
  • Causing or involving a reduction in expenditure. 

noun
  • A reduction in expenditure, often as a result of financial restrictions. 

waning

adj
  • Becoming weaker or smaller. 

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

noun
  • The fact or act of becoming smaller. 

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

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