An evening dress, also called a gown[source needed], was an item of clothing.
Many ladies wore evening dresses in 1813 including Ruby Sunday in a royal yellow one, the Duchess of Pemberton and the member of the Chuldur who took her place in a Prussian blue one, and Emily Beckett in a turquoise one. (TV: Rogue [+]Loading...["Rogue (TV story)"])
The Siren appeared to the crew of the Fancy wearing a white evening dress. (TV: The Curse of the Black Spot)