dress suit vs morning dress

dress suit

noun
  • A type of formal attire for women, typically a jacket over a dress, or a jacket and blouse with trousers or a skirt. 

  • A type of formal attire for men, normally consisting of a jacket (traditionally with tails), trousers, waistcoat, shirt and tie (traditionally a bow tie). 

morning dress

noun
  • A woman's dress designed for informal day wear. 

  • 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. 

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