Abyss :: Abyss (n.) A bottomless or unfathomed depth, gulf, or chasm; hence, any deep, immeasurable, and, specifically, hell, or the bottomless pit..
Abyss :: Abyss (n.) Infinite time; a vast intellectual or moral depth.
Abyss :: Abyss (n.) The center of an escutcheon.
Abyssal :: Abyssal (a.) Belonging to, or resembling, an abyss; unfathomable..