'Gloom' in the Bible

So we have the prophetic word made more certain. You do well to pay [close] attention to it as to a lamp shining in a dark place, until the day dawns and light breaks through the gloom and the morning star arises in your hearts.

For if God did not [even] spare angels that sinned, but threw them into hell and sent them to pits of gloom to be kept [there] for judgment;

These [false teachers] are springs without water and mists driven by a tempest, for whom is reserved the gloom of black darkness.