This is a fleur noir maxi slip dress in a size large by Dress Forum which is sometimes sold at Anthropologie. I'm unsure if this was. Fabric is called Midnight Garden. Satin slip dress with flutter sleeves giving a whimsical fairy grunge Cottagecore dark romantic Whimsigoth look. Hand wash. Polyester with polyester lining.
Approximate measurements;
Underarm to underarm: 17.5 inches Waist flat: 16 inches Adjustable straps Hips flat: 20 inches Length from underarm Since straps are adjustable: 46.5 inches