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 200 BC 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.