APSU. - This is a Sumerian word Semitized as zu-ab in Sumerian and read abzu, meaning “house of wisdom” (?). This etymology (ab “house,” zu “wisdom”) is necessarily correlated with the fact that A. is the dwelling of Ea, god of wisdom. The A., dwelling of the wise god, is the mass of water on which the earth rests and which surrounds II. The A. is both above and below the earth; from the A. above, from the heavens, come the rains, and from the A. below, the waters of rivers and streams that fertilize the earth. A similar cosmogonic conception is found in Genesis. Some suppose that the Greek ἄβυσσος and the derivatives in Indo-European languages also derive from this Sumerian term.
A. is also a male deity, “the ocean of fresh water,” whose mother is the goddess Tiamat, “the ocean of salt water.” The god A. is then slain by the god Ea. It may be from this legend that A. becomes the dwelling of the god Ea.