Going by the 18th century-specific tertiary terms listed below "gown" in Nomenclature 3.0 - "gown, round" and "gown, open" - it's probably meant to be used specifically for clothing from the 18th century. At that time, women's skirted garments were referred to as gowns instead of dresses. "Dress" works for roughly everything after that, whether one-piece or two-piece.

"Gown, evening" refers to 19thc., 20thc. or modern women's evening wear, but if you aren't certain of being able to determine if a dress is for the day or evening, I would suggest just using "dress" (or emailing me off-list, I'm happy to assist in IDing clothing!) and describing it fully in the record. There's also "gown, tea", which refers to a very specific type of dress worn in the late 19th century, usually made with a looser fit or with the illusion of it, and again, it's better to revert to "dress" if you're not sure. You also have "gown, academic" and "gown, baptismal", which are a little more self-explanatory.

I hope this is helpful!

Cassidy Percoco

Curator

St. Lawrence County Historical Association

3 E Main St | PO Box 8

Canton, NY 13617

(315) 386-8133