bedgown vs covers

bedgown

noun
  • An article of women's clothing for the upper body, usually thigh-length and wrapping or tying in front; a bedjacket. 

  • A nightgown. 

covers

noun
  • The bedclothes; collectively, the sheets, blankets, etc. 

  • The tarpaulins or other devices used to cover the wicket during rain, in order to prevent it getting wet. 

  • The area of the field near cover and extra cover. 

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