Meaning

noun the time that the curfew signal is sounded

noun a signal (usually a bell) announcing the start of curfew restrictions

noun an order that after a specific time certain activities (as being outside on the streets) are prohibited

originFrom Middle English curfu, from Old French cuevre-fu (French couvre-feu), from the imperative of covrir (“to cover”) + fu (“fire”). Compare kerchief.

Etymology from Wiktionary, CC BY-SA 3.0