glad rags vs peignoir

glad rags

noun
  • Stylish clothing. 

  • Formal attire, dress clothes. 

peignoir

noun
  • A long outer garment for women, usually sheer and made of chiffon and often sold with matching nightgown, negligee or underwear 

  • A cape worn to protect the clothes at the barbers / hairdressers 

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