A surtout is a type of coat that is long and often worn over other clothes.
Surtouts are usually seen as formal and elegant.
Examples:
He wore a black surtout over his suit.
The lady's surtout was very fancy.
The long surtout kept him warm in the cold weather.
She looked very important in her long surtout.
The king's surtout was made of the finest cloth.
The superhero wore a colorful surtout over his costume.