Hades three-headed guard dog Cerberus. The Etruscan god Aita and the Roman gods Dis Pater and Orcus were eventually taken as equivalent to Hades and merged into Pluto, a Latinization of Plouton (", Ploútōn"), itself a euphemistic title often given to Hades. The origin of Hades' name is uncertain, but has generally been seen as meaning "the unseen one" since antiquity. An extensive section of Plato's dialogue "Cratylus" is devoted to the etymology of the god's name, in which Socrates is arguing for a folk etymology not from "unseen" but from "his knowledge ("eidenai") of all noble things". Modern linguists have
Sinmara Orcus, a god of the underworld in Roman mythology, and that Hel is blue or half blue and half light, like the Roman goddess Proserpina, whom Saxo equates to Hel in his "Gesta Danorum". Falk further notes that Sinmara is referred to as "aurglasis Eirr", which he translates as "the goddess of the gold ring", and compares Hel's being called "Gjallar sunnu gátt" "wearer of the necklace" in stanza 9 of the poem "Forspjallsljóð". Björn Olsen associates the kenning with "veðurglasir", a name of Yggdrasill in stanza 24 of the same poem, and translates "aurglasir" as a name for the