curfew [ME] Today a curfew is sometimes imposed during periods of emergency or conflict, as a way of keeping people off the streets, usually at night. In the Middle Ages, though, the curfew was the time by which people had to put out or cover the fire in their hearth—the objective was not to keep order but to stop houses burning down. Curfew is an Old French word, from cuvrir ‘to cover’ and feu ‘fire’.