Jupiter

Jupiter comes from Latin Iūpiter, meaning "father Jove," which traces back to Proto-Italic *djous patēr, literally "sky father." That in turn descends from Proto-Indo-European *dyḗws ("the bright one") joined with *ph₂tḗr ("father").

The name stayed remarkably close to its roots: from a compound meaning "sky father" in a very old Italic language, it settled into Latin as the name of the chief god, and later became the name of the largest planet.

It's a doublet of Dyaus Pita, the Vedic sky-father, and a cognate of Ancient Greek Zeû páter ("father Zeus") — both descend from the same PIE roots for "bright sky" and "father."