What does abyss mean?
The definition of abyss
A*byss”, n.
Etym: [L. abyssus a bottomless gulf, fr. Gr.

1 A bottomless or unfathomed depth, gulf, or chasm; hence, any deep, immeasurable, and, specifically, hell, or the bottomless pit. Ye powers and spirits of this nethermost abyss. Milton. The throne is darkness, in the abyss of light. Dryden.
2 Infinite time; a vast intellectual or moral depth. The abysses of metaphysical theology. Macaulay. In unfathomable abysses of disgrace. Burke.
3 (Her.)
The center of an escutcheon.

Note: This word, in its leading uses, is associated with the cosmological notions of the Hebrews, having reference to a supposed illimitable mass of waters from which our earth sprung, and beneath whose profound depths the wicked were punished. Encyc. Brit.