Apsu

'Apsu' is the personified great 'ocean' -- the 'Deep' that covers everything.

The Religion of Babylonia and Assyria Morris Jastrow 1891

It lay in the lowest part of the mountain that represented the earth, not far from the hollow underneath the mountain into which the 'Apsu' flowed.

The Religion of Babylonia and Assyria Morris Jastrow 1891

Page 428, Volume 1 the “Gate of the Apsu” — Apsu designating the waters of chaos before Creation.

THE CITY MOSHE BARASCH 1968

Throughout all periods of Babylonian-Assyrian history, the conception prevailed of a large dark cavern below the earth, not far from the Apsu -- the ocean encircling and flowing underneath the earth -- in which all the dead were gathered and where they led a miserable existence of inactivity amid gloom and dust.

Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon" Various

The universe begins with a double, purely material, principle, Apsu and Tiamtu, male and female, probably personifying the mass of salt and sweet water, mixed into one.

The Catholic Encyclopedia, Volume 7: Gregory XII-Infallability 1840-1916 1913

Apsu and Tiamet, male and female, probably personifying the mass of salt and sweet water "mixed together in one".

The Catholic Encyclopedia, Volume 4: Clandestinity-Diocesan Chancery 1840-1916 1913

The Greek copyist had evidently mistaken LACHOS for DACHOS, but otherwise the two accounts tally exactly; Apason is Apsu the Ocean;

The Catholic Encyclopedia, Volume 4: Clandestinity-Diocesan Chancery 1840-1916 1913

Then Apsu called upon Mummu, his counsellor, the son who shared his desires, and said, "O Mummu, thou who art pleasing unto me, let us go forth together unto Tiamat and speak with her."

Myths of Babylonia and Assyria Donald Alexander Mackenzie 1904

Ea, as we have seen, symbolized the beneficence of the waters; their destructive force was represented by Tiamat or Tiawath, the dragon, and Apsu, her husband, the arch-enemy of the gods.

Myths of Babylonia and Assyria Donald Alexander Mackenzie 1904

Nu is represented in Babylonian mythology by Apsu-Rishtu, and Nut by

Myths of Babylonia and Assyria Donald Alexander Mackenzie 1904