An often understood garment from ancient Rome; the "toga" of a toga party is much scantier and flimsier than the toga that ancient Romans wore.
The toga was basically a large wrap worn over a tunic.
In the early days of the empire, the toga was worn by both sexes, but after 200BC the toga was reserved for men while women were expected to wear the stola; a woman wearing a toga was generally a prostitute or an adultress, to distinguish them from "respectable" women.