The story
Latin; in sense 1, from chiasma, from Ancient Greek χίασμα (khiasma); in sense 2, from chiasmus, from Ancient Greek χιασμός (khiasmos "crossing, diagonal arrangement"), from χιάζειν (khiázein, “to mark with a chi”), from χ (kh, “chi”)
Etymology from Wiktionary, CC BY-SA 4.0.