The Hattic word arinna
Word arinna
Meaning fountain, spring
Notes/Remarks The etymology of this word is uncertain
See also Pre-Greek toponyms: Λέρνα ‘hydronym, place name’
Pre-Greek toponyms: Άρνη ‘place name, town name’
Synonyms ura/uri

Comments
See David M. Weeks, 1985/2006 on his comments about the Hittite word for sea:

Hattic origin, from the place-name URUArinna (URUTÚL-na) via *arinna- ‘fountain’.