pillowslip vs quilt

pillowslip

noun
  • A pillow case. 

quilt

noun
  • A bed covering consisting of two layers of fabric stitched together, with insulation between, often having a decorative design. 

  • A quilted skirt worn by women. 

  • A roll of material with sound-absorbing properties, used in soundproofing. 

verb
  • To construct a quilt. 

  • To construct something, such as clothing, using the same technique. 

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