allayment vs belt-tightening

allayment

noun
  • Something that allays; mitigation 

belt-tightening

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

adj
  • Causing or involving a reduction in expenditure. 

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