sehstein
From Proto-Germanic *sehstehun. Compare Old Frisian sextīne, Old English siextīene, Old High German sehszehan, Old Norse sextán, Gothic 𐍃𐌰𐌹𐌷𐍃𐍄𐌰𐌹𐌷𐌿𐌽 (saihstaihun).