His name is identical with the Hittite word for the sea, which could also refer to bodies of water, treated as numina rather than personified deities.
[1] The word aruna means sea in Hittite, though according to Gernot Wilhelm it is possible that it was a loan from Hattic, as no plausible Indo-European etymology has been identified for it so far.
[5] While there is no direct evidence for a distinct cult of a sea deity in central Anatolia, Volkert Haas proposed such a tradition might have also existed in this area based on the discovery of literary texts involving Aruna which originated there.
[6] In a ritual from the Middle Hittite period dedicated to the goddess Ḫuwaššanna, Aruna appears alongside Anna, Zarniza and Šarmamma.
[10] A festival involving Aruna, as well as Ḫudumana (or Ḫurdumana; otherwise unattested[11]) and a deity designated by the logogram IŠTAR (Shaushka in Gary Beckman's translation[12]), was celebrated in the city of Tuwanuwa, corresponding to later Tyana, located in the proximity of modern Bor.
[16] The word is written in this text with a logogram, A.AB.BA, and without the divine determinative, but Ian Rutherford nonetheless presumes that a connection with the worship of Aruna in nearby Tuwanuwa is possible.
[4] A "ritual of the sea" (A-NA ZAG a-ru-na-aš; CTH 436) performed by kings after return from a military campaign was supposed to affirm the continuity of the borders of their domain and eliminate impurity.
[23] As a result, the world drowns in darkness,[24] which prompts Tarḫunna, the weather god, to send his firstborn son Telipinu to retrieve him.
[23] Aruna apparently sent a messenger, possibly represented as a personified river, to demand a bride price from the storm god, prompting the latter to consult Ḫannaḫanna about the best course of action to take.
[34] Occasionally the sea was a metaphorical designation of distant locations or borders of the Hittite realm, as in the case of a ritual stating that the goddesses Istustaya and Papaya lived on its shores.
[22] The sea was also believed to be the residence of three goddesses bearing the name Ammama, presumably related to the traditions of the city of Zalpa,[35] though their point of origin might have been the Mediterranean coast.