Fr: habit=garment, i.e. a general term for clothing.
A descendant of the justaucorps, the frac shared with it the general shape of a not quite knee-length jacket with long, narrow sleeves. It had a high standing collar, small sleeve cuffs, the buttonholes weren't too conspicuous anymore, and there were no pleats in the side back seams. The front edge was cut in a long curve that merged into two tails at the side seams of the breeches. Very fashionable around the revolution, before the Terror made it unwise to wear culottes.
Habit à la franšaise, 1780/90s