Titan (language)

The language of the titans and the titan-forged is known as Titan. It is written in runes.

Vanir and Aesir are apparently two dialects of Titan.

Wrathion can read Titan. In the past, the mogu could read and write it.

Titan primer
Here are a few common Titan phrases and words, for which the translations have been officially confirmed by Blizzard:
 * Aesir = Storm Giants.
 * Kalimdor = Land of eternal starlight.
 * Nalak = Serpent. May be specific to the mogu.
 * Vanir = Earth Giants.

Untranslated Titan words or phrases

 * Aggramar - A titan.
 * Aman'Thul - A titan.
 * Echomok - A cavern located inside Uldaman.
 * Eonar - A titan.
 * Gni'kiv - A component of the Staff of Prehistoria.
 * Golganneth - A titan.
 * Khaz'goroth - A titan.
 * Khaz'mul - A chamber containing the secrets of Uldaman, unlocked by the Staff of Prehistoria.
 * Kol-tharish - A phrase yelled by Kologarn when killing a player.
 * Norgannon - A titan.
 * Revola ruk maez amir - Said by Magni Bronzebeard to open the door to the Primordial Observatory.
 * Sargeras - A titan.
 * Terramok - A vault of the titans located deep within Maraudon.
 * Tsol - A component of the Staff of Prehistoria.
 * Uldaman - An earthen complex buried deep within the mountains.
 * Uldir - A titan research and quarantine facility where experiments on the Old Gods were conducted.
 * Uldis - A titan facility located beneath the Temple of Storms in the Storm Peaks.
 * Ulduar - The largest titan-forged complex on Azeroth.
 * Uldum - A zone in southern Kalimdor that acts as a titan superweapon with the capability of scouring all life from Azeroth.
 * Val'anyr - A hammer crafted by the titans themselves and given to Urel Stoneheart.

Word speculation

 * Aes = Storm.
 * Gor = Dark.
 * -ir = Giant (suffix).
 * Ribal = Seether.
 * Shalach = Rend.
 * Tael = Flame.
 * Van = Earth.

In the RPG
The written language is made up of glyphs (hieroglyphs) and is understood only by deduction. Scholars are trying to restore the language by matching the modern Dwarven tongue with rare evidence at excavations of Titan ruins. Linguists tear their hair out trying to parse the inhumanoid grammar and circular references of Titan.
 * Gorribal = "Dark Seether"
 * Gorshalach = "Dark Render"
 * Taeshalach = "Flame Rend"
 * Uld = City; according to Brann Bronzebeard, one of the reasons he believes Ulduar is a titan city is because its name starts with "Uld". However, this translation is not specifically confirmed. His gossip text in Stormheim says there is no "Uld-anything" in the area, despite the high titan influence.

Titan-speaking player characters
Beginning with Wrath of the Lich King, a small number of rogue player characters of both factions were granted the ability to speak and understand Titan in the same way as other in-game languages, regardless of faction, and could thus use it to communicate cross-faction.

The language was not limited by character level, race or faction, and no links to specific in-game actions were proven. One poster on the official forums claimed that, when asked about it, a GM told him that it was not a bug, but refused to elaborate on the purpose. However, no actual proof was presented of a GM having said this. Several other players have also claimed to have spoken to GMs or Blizzard representatives regarding the ability, some reporting a similar answer.

A similar mysterious learning of the Draconic language by many player characters, in this case limited to gnome rogues, happened around the same time, with some learning both languages.

With Patch 5.0.4 the supposed bug was apparently removed.

Speculation
Due to being descendants of the titan-forged, a number of Azerothian languages—Common, Dwarven, Gnomish, Vrykul, Mogu, and Tol'vir—might have originated from the Titan language.