Hades is the most recent form of his name… The meaning of Ais, Aides or Hades is most probably ‘the invisible’ or ‘the invisibility-giving’, in contrast with Helios, the visible and visible-making.
Keréñyi establishes the etymological polarity at the heart of the Apollo-Hades tension by defining Hades as structural antithesis to solar visibility, the foundational move for all depth-psychological elaborations of this pairing.
, The Gods of the Greeks, 1951thesis