dressing gown

noun1

1. •
   (UK, Ireland) An item of clothing often made from cotton or another absorbent material, in the form of a long open robe with a belt to tie it around the middle and fasten it securely; often worn over pyjamas.

   • After about ten minutes he got up, and, throwing on an elaborate dressing-gown of silk-embroidered cashmere wool, passed into the onyx-paved bathroom. — 1891