chelydre (plural chelydres)
chelȳdre
From Middle English chelidre, chelyder, chelydre, from Old French chelidre, chelydre, from Latin chelȳdrus (“fetid water serpent”), from Ancient Greek χέλυδρος (khéludros, “amphibious serpent”), from χέλυς (khélus, “tortoise”) + ὕδρος (húdros, “water serpent”). Cognate of French chélydre.