Vintage 2000s gothic strapless corset back prom dress. Has one small tear on the side, see photos.
This one has a tie back with a zipper below it. Tagged size 15/16, has lots of give in the bust and waist and can fit much smaller.

Flat lay measurements: (measured taken out a bit)
Chest: 19 inches
Waist: 17 inches
Hip: 38 inches
Length: 54 inches