bedgown vs nightrobe

bedgown

noun
  • A nightgown. 

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

nightrobe

noun
  • A robe to be worn at night; a nightgown. 

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