Abyss

Abyss is primarily and classically an adjective, meaning deep, very deep (Wisd.

From the 1913 Catholic Encyclopedia

Abyss (Greek ἄβυσσος), is primarily and classically an adjective, meaning deep, very deep (Wisd. x, 19; Job. xxxviii, 16). Elsewhere in the Bible, and once in Diog. Laert., it is a substantive. Some thirty times in the Septuagint it is the equivalent of the Hebrew tēhóm, Assyrian tihamtu, and once each of the Hebrew miçūlah, "sea-deep", çūlah, "deep flood", and rāchābh, "spacious place". Hence the meanings: (1) primeval waters; (2) the waters beneath the earth; (3) the upper seas and rivers; (4) the abode of the dead, limbo; (5) the abode of the evil spirits, hell. The last two meanings are the only ones found in the New Testament.