I had a Professor in undergrad who would read the homeric Greek versions of texts aloud to the class, and as he would read them, he’d stop to discuss certain puns or phrases that he thought had yet to see proper translation into English and other modern languages and how mistranslation has shaped our understanding of what the text was saying. In particular, I remember him discussing how “Hades,” which often refers to the God of the Underworld, is a figure of speech that literally means “unseen” or “beneath sight”; he then mentioned that translations of this word have instead preferred to interpret the figure of speech as literally indicating a place beneath the visible world rather than preserving the word’s figurative basis. We were reading the Iliad. While I’m sure the word “Hades” is used in a variety of ways, is there any truth to what my professor was saying? What good sources exist regarding this issue?
I mean, yeah that's what Ἅιδης probably means. It's certainly how the word is typically used in Homer, for whom Hades is a place and only somewhat rarely (e.g. Il. 5.385) a person. Attic Greek has a peculiar aspirated form of the word, which gives us Anglicized "Hades," but in all other Greek dialects the word is unaspirated Aides. Forms referring to the person also make it clear that the word probably originally refers to a place, since the person is often called Ais or Aedoneus, which should be adjectives referring to Aides. The generally accepted etymology for Ἅιδης is alpha-privative plus ἰδεῖν, to see, i.e. "unseen," although it's a little unclear why exactly if this is the case Attic Greek added an aspirate to the beginning of the word. There isn't really anything terribly controversial about this. The etymology is a little contested, but it's pretty widely accepted and it's universally acknowledged that Homer uses Ἅιδης to refer to a place first and foremost, which interestingly Odysseus in Od. 11 associates as being ruled by Persephone first and foremost, rather than a god.