The root occurs probably in the Annedotus and Oannes of Berosus, as well as in Philo-Byblius's Anobret.
In its origin it is probably Cushite: but it was adopted by the Assyrians, who inflected the word which was indeclinable in the Chaldaean tongue, making the nominative Anu, the genitive Ani, and the accusative Ana.
Ana is the head of the first Triad, which follows immediately after the obscure god Ra.

His position is well marked by Damascius, who gives the three gods, Anus, Illinus, and Aus, as next in succession to the primeval pair, Assorus and Missara.

He corresponds in many respects to the classical Hades or Pluto, who, like him, heads the triad to which he belongs.

His epithets are chiefly such as mark priority and antiquity.
He is called "the old Ana," "the original chief," perhaps in one place "the father of the gods," and also "the Lord of spirits and demons." Again, he bears a number of titles which serve to connect him with the infernal regions.

He is "the king of the lower world," the "Lord of darkness" or "death," "the ruler of the far-off city," and the like.