eiderdown vs sheets

eiderdown

noun
  • The down of the eider duck, used for stuffing pillows and quilts. 

  • A quilt stuffed with this down. 

sheets

noun
  • Collective noun meaning a large amount, when used of rain, or other precipitation. 

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