1. set time when a person (or people) must be indoors; signal or bell that announces the start of curfew restrictions; decree ordering that after a specific time specific activities outside on the streets are forbidden by law; length of time during which a curfew is in effect. curfewcurfew (kûrfū), n. [oe. courfew, curfu, fr. of. cuevrefu, covrefeu, f. couvre-feu; covrir to cover + feu fire, fr. l. focus fireplace, hearth. see: cover, and focus.]