muumuu vs peignoir

muumuu

noun
  • A long loose-fitting dress made of lightweight fabric printed with bright, stylized Hawaiian themes (such as flowers and palm branches). 

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