Hades
wiktionary
From Ancient Greek ᾍδης(Hā́idēs). Possibly Proto-Indo-European *n̥-(“not”) + *weyd-(“see”), meaning "that which is unseen", [1] equivalent to ἀ-(a-) + εἶδον(eîdon). Puhvel (1987) argues that it is from *Sm̥weyd-, from *sm̥-(compounding stem) + *weyd-(“see”), meaning "see-together" or "uniter", equivalent to ἁ-(ha-) + εἶδον(eîdon), cognate with Russian свида́ние(svidánije, “see each other”), and partly in Sanskrit संगमनम् जनानां(saṃgamanam janānāṃ, literally “ingatherer of people”), where *weyd- is replaced with *gem-.
etymonline
Hades
"god of the dead in Greek mythology;" also the name of his realm, the abode of the dead spirits, 1590s, from Greek Haidēs, in Homer the name of the god of the underworld, son of Kronos and Rhea, brother of Zeus and Poseidon. His name is of unknown origin. Perhaps literally "the invisible" [Watkins], from privative prefix a- + idein "to see" (from PIE root *weid- "to see"). The name of the god was extended in later Greek writing to his kingdom, also "the grave, death." Related: Hadal (adj.), 1964; Hadean.
