The story
- Greek · derived fromχάσματα
- Italian · derived fromcasamatta
- French · borrowed fromcasemate
- English todaycasemate
From French casemate, from Italian casamatta. Further origin unclear, could be a compound casa (“house”) + matta (“mat (of straw), roof made of such material”), or borrowed from Greek χάσματα (chásmata) the plural of χάσμα (chásma, “gap”), presumably referring to the loopholes for shooting from.
Etymology from Wiktionary, CC BY-SA 4.0.