Volume 1: 1771 Edition of the Encyclopedia Britannica!
Abyss, in a general sense, signifies any unfathomable gulph. It is also the name of a vast cavern filled with water, supposed to exist near the centre of the earth.
Abyss, in Scripture, is sometimes used for hell.
Abyss, in antiquity, a name given to the temple of Proserpine.
Abyss, among alchemists, signifies the receptacle of the seminal matter, and sometimes the seminal matter itself.