Where does “ύπνος” come from?
ύπνος (Greek) comes from Ancient Greek ὕπνος, from Proto-Hellenic húpnos, from Proto-Indo-European supnós, from Proto-Indo-European swóp-r̥ ~ swép-n̥s, from Proto-Indo-European swep- — to sleep.
ύπνος (Greek): sleep
Ancestry of “ύπνος”, step by step