Ak?ka?di?an or Ac?ca?di?an (??ke? di ?n, ??k?-) n. 1. an extinct eastern Semitic language of Assyria and Babylonia, written in a cuneiform syllabary borrowed from Sumerian. 2. a native or inhabitant of Akkad. adj. 3. of or pertaining to the language Akkadian. 4. of or pertaining to Akkad or its inhabitants. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.