Etymology tree Proto-Indo-European *kéh₂i-lom Proto-Italic *kailom? Latin caelum Latin terrestris Latin -estris Latin caelestis Proto-Indo-European *-nós Proto-Indo-European *-iHnos Proto-Italic *-īnos Latin -īnus Latin caelestinus Latin Caelestinuslbor. English Celestine Learned borrowing from Latin Caelestinus.