How to say "autumn, fall" in Arabic

Same root as חורף, 'winter' — regular خ↔ח — which makes this a classic trap: kharīf and חורף sound like a matching pair, but they name different seasons. Both descend from a Common Semitic root for 'the rainy/harsh season' (compare Akkadian ḫarpu, Ge'ez ḫaraf); it just settled on a different stretch of the calendar in each language — the defining rains fall in autumn in the Arabian Peninsula but in winter in the Land of Israel.