curfew

Etymology

From Middle English curfeu,^[1][2] borrowed from Anglo-Norman coeverfu,^[3][2] from Old French cuevrefeu (“cover fire”) (modern French couvre-feu),^[1][2] from cuevre, imperative of covrir “to cover”, + feu “fire”,^[3][2] the latter from Latin focus (“hearth”).^[1][4]

The word named the evening signal to bank the hearth fires,^[4][2] a medieval practice meant to prevent fires from untended hearths.^[2] The extended sense “periodic restriction of movement” had developed by the 1800s.^[2] Compare cover and kerchief.^[5]

References

1. [1] [2] [3] The American Heritage Dictionary of the English Language, Boston: Houghton Mifflin
2. [1] [2] [3] [4] [5] [6] [7] Harper, Douglas, Online Etymology Dictionary, https://www.etymonline.com
3. [1] [2] Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
4. [1] [2] Merriam-Webster's Collegiate Dictionary, Springfield, Mass.: Merriam-Webster
5. [1] Wiktionary, the free dictionary, https://en.wiktionary.org