Gemini
Borrowed from Latin geminī, plural of geminus “Zwilling”, calque of Ancient Greek Δίδυμοι (Dídumoi).
Perhaps identical with the above (compare Latin ēdepol (“by Pollux”), ēcastor (“by Castor”)), but perhaps more likely distinct in origin: compare Dutch jemenie, jemie, German gemine, jemine, Czech jémine, all ultimately shortened from Latin Iēsū domine (“O Lord Jesus”).