Observers used the term sans-culottes (French for without knee-breeches), originally during the early years of the French Revolution to refer to the ill-clad and ill-equipped volunteers of the Revolutionary army, and later generally to the ultrademocrats of the Revolution.

The sans-culottes were for the most part members of the poorer classes, or leaders of the populace, but during the Reign of Terror, public functionaries and persons of good education styled themselves citoyens sans-culottes.

The distinctive costume of typical sans-culottes featured:

• the pantalon (long trousers) - in place of the culottes (knee-breeches) worn by the upper classes
• the carmagnole (short-skirted coat)
• the red cap of liberty
• sabots (wooden shoes).

The influence of the sans-culottes ceased with the reaction that followed the fall of Robespierre (July 1794), and the name itself became proscribed.

The Republican Calendar at first termed the complementary days at the end of the year Sans-culottides; however, the National Convention suppressed the name when adopting the constitution of the year III (1795) and substituted the name jours complémentaires.