any of several ancient cities of SW Asia, founded by Seleucus I; esp., the chief city of the Seleucid Empire, on the Tigris
See Seleucia in American Heritage Dictionary 4
An ancient city of Mesopotamia on the Tigris River south-southeast of modern Baghdad. Founded c. 300 B.C., it was an important commercial center and the chief city of the empire founded by Seleucus I.