Chemise

A chemise is the basic female undergarment worn mostly by women, closely resembling a modern nightgown, and functioning like a modern slip. It was extensively worn by ladies of all ranks of society in the middle ages and Renaissance. A chemise was always worn under a lady's dress and corsetry. The male equivelant was an undertunic.

A chemise had the function of both protecting the wearer's skin from the more uncomfortable features of Medieval and Renaissance women's clothing such as stiff embroidery, laces, or pins, and it also protected the clothing from things like sweat and odor. Before modern dry-cleaning, elaborate gowns were not very washable, especially if they had boned corsetry, embriodery made of actual metal thread and gemstones, or were made of delicate materials. Even today in the 21st century, it is not advised that a person wash a traditional boned corset for fear of ruining a garment that can cost several hundred US dollars.

Unlike modern undergarments, it was perfectly acceptable for a chemise to be seen under clothing, such as through puffed sleeves, under the hemlines of skirts, etc, though obviously the amount of chemise showing would need to be tasteful.

Hauvon Expanded Universe
Sabina used the hem of her chemise to make emergency bandages in My Envied Lady when no other suitable cloth was available. It is assumed most human woman in HEU wear a chemise, though undergarments are obviously not talked about much in mixed company.