Shawn Foster wrote:
The line between “nightgown” and “dress” is…wobbly. The Victorians would agree with your “waist definition” delineation, I think, but in current fashion it’s quite less clear. I’ve seen plenty of items marketed as nightwear that I’d absolutely wear as day clothing (though generally not to an office job, even on the very casual West Coast USA), and dresses I’d be fine with wearing as nightwear.
Yes, contemporary swing dress or tent dress can be quite flattering without a waist seam.
The problem I have with loose dresses without holding in the waist is that unless the neckline is fairly small, otherwise when I bend over, people in front of me would be able to see my underwear all the way to my toes!