The story
- Latin · calque ofquadratum magicum
- French · calque ofquarré magique
- English todaymagic square
As magical square by 1670 and magic square by 1701 (see Citations). Calque of French quarré magique or Latin quadratum magicum. Magic refers to its original function as a talisman.
Etymology from Wiktionary, CC BY-SA 4.0.