cotillion vs underslip

cotillion

noun
  • A kind of woollen material for women's skirts. 

  • The music regulating the cotillion. 

  • A bold dance performed in groups of eight where women lift their skirts to display their ankles. 

verb
  • To dance the cotillion. 

underslip

noun
  • A woman's undergarment. 

  • An underlying layer of slip. 

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