As to the meaning, here is an excerpt from Wikipedia:

Origin of the Name

The form Agade is Sumerian — appearing, for example, in the Sumerian king list; the later Assyro-Babylonian form Akkadû (“of or belonging to Akkad”) was likely derived from this. It is possible that the Sumerian name, despite its unetymological spelling of A.GA.DÈ, is from AGA.DÈ, meaning “Crown of Fire”[2] in allusion to Ishtar, “the brilliant goddess”, whose cult was observed from very early times in Agade. Centuries later, the neo-Babylonian king Nabonidus mentioned in his archaeological records[3] that Ishtar worship in Agade was later superseded by that of the goddess Anunit, whose shrine was at Sippar—suggesting proximity of Sippar and Agade. (There were actually two cities named Sippar—one under the protection of Shamash, the sun-god, and the one under Anunit.) One theory holds that Agade was situated opposite Sippar on the left bank of the Euphrates, and was perhaps the oldest part of the city of Sippar. Another theory is that the ruins of Akkad are to be found beneath modern Baghdad.

Despite numerous searches, the city has never been found. Reputedly it was destroyed by invading Gutians with the fall of the Akkadian Empire.

The city of Akkad is mentioned once in the Tanakh (Genesis 10:10). The Greek (LXX) spelling is Archad.

And the beginning of his (Nimrod’s) kingdom was Babel, and Erech, and Accad, and Calneh, in the land of Shinar (KJV).

Akkadian may refer to:

* Akkadian language

* City of Akkad or Agad

* Akkadian Empire

* Sargon of Akkad

* The Amarna letters

If so, it’s an ancient Mesopotamian language