In any way of speaking, there is always progression in language. New words are invented, and old ones considered irrelevant are promptly forgotten. That is the way of life.
When doing research and coming across new words, it's been really interesting to learn about various terms and what they mean.
A 'wrapper' is a handy dandy little robe. Styles vary from looking more like a dress, to an elaborate loose-fitting garment thing, to a maternity robe.
What defines a wrapper from any other dress is that they were loose-fitting or had a drawstring waist. That is how the dress look is accomplished; the drawstring waist makes it look gathered-to-fit. Some of them button from the neck all the way to the floor.
From what I can tell, wrappers could be functional as a work-type dress, depending on the style. I've seen wrappers in cotton, wool, and silk. Obviously, you might want to save your silk garments for indoors.
Wrappers were supposed to be comfortable; like a robe nowadays, no one was really supposed to see you in them, giving you liberty to wear whatever you want underneath. Some were large enough to wear a hoop skirt underneath, although that was matter of personal preference. Sort in the way that bras become tiresome to wear after a while, having something that didn't require a corset would be nice. The one below shows what they look like without any kind of drawstring or waistband.
You know, maybe I should make one. Just cause. It wouldn't be too different from a cotton work dress, but it would be something new. Not that I plan on being pregnant any time soon.