In Greek
mythology, Tartaros (also Tartarus) is both a deity and a place in
the underworld even lower than Hades. In ancient orphic sources and in
the mystery schools Tartaros is also the unbounded first-existing "thing" from which the Light and the cosmos is born.
2 Peter 2:4: "God did not hold back from punishing
the angels that sinned, but, by throwing them into Tartaros,
delivered them into pits of dense darkness to be reserved for
judgement."