morning dress

Short definition from Wiktionary

Noun

1. 1
   A woman's dress designed for informal day wear.
2. 2
   Clothing to be worn in the morning or daytime, as opposed to the evening; now (specifically), a man's formal suit consisting of a (usually) dark grey morning coat, waistcoat and striped trousers accompanied with a top hat, white shirt and tie or cravat.