From Longman Dictionary of Contemporary Englishnightdressnight‧dress /ˈnaɪtdres/ noun [countable] DCCa piece of clothing, like a thin dress, that a woman wears in bed
Examples from the Corpus
nightdress• She was in her nightdress, bare legs and large slippers.• Women in nightdresses peeping out of roadside houses lent a surreptitious air to the first few miles.• That evening he came to my room, to see how I looked in my new nightdress.• The programme showed a children's nightdress which is sold in the shops for £1.10.• She pulled the nightdress over her head.• First Price, a retailer selling the nightdress, said it would look at buying from abroad instead if this happened.• She looked tall in her long white nightdress, her long dark hair hanging down her back to her waist. 