An institution supposed to have been introduced into England hy order of william the Conqueror, which consisted in the ringing of a bell or bells at eight o’clock at night, at which signal the people were required to extinguish all lights in their dwellings, and to put out or rake up thelr fires, and retire to rest, and all companies to disperse. The word is probably derived from the French couxre feu, to cover the fire
Source: Black’s Law Dictionary 2nd Ed (1910)
