chaque m, f (invariable)
Cognate to Middle French chasque (“each”), a back-formation from Old French chascun (“each one, every one”).
chaque m, f (invariable, masculine and feminine plural chaques)
From Middle French chasque, back-formed from chascun (cf. modern French chacun), by removing the un. Old French chascun derives from a Vulgar Latin *cascunum, from a crossing of quisque unus with catunum < cata unum. Latin cata derives from Ancient Greek κατά (katá) (compare Catalan, Spanish, and Portuguese cada).