housecoat vs peignoir

housecoat

noun
  • A longish dress-like garment of one piece, fastening down the front, worn about the house. 

  • A bathrobe or dressing gown. 

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 housecoat and peignoir occurred in a corpus of books? (source: Google Ngram Viewer )