The current styles were founded in the revolution during the early 19th century that sharply changed the elaborately embroidered and jewelled formal clothing into the simpler clothing of the British Regency period, which gradually evolved to the stark formality of the Victorian era. It was in the search for more comfort that the loosening of rules gave rise in the late 19th century to the modern lounge suit.
It's a Kaftan sort of thing, but the sleeves could be called batwing sleeves. So it could be called a batwing dress
Yes, It is called Dress...
It's a dress.
