"Frock" is exactly what I should call this dress, even though I don't really like the word.
I found this -frock- on Etsy for an excellent price, and was so pleased to find it in amazing condition when it arrived. It's wool and neither has moth holes nor stinks of mothballs! The interior is unlabeled, with hand-overcast raw edges, some french seams, and clever use of selvedge. It retains some basting stitches, and even has a quick nip in on the side seams to slim it a bit through the waist (which I have totally done on my 1920s projects!).
|Some interesting and typical seaming on the skirt makes this more than just a sack.|
Look for this one in a future Royal Vintage photo shoot. :)