Babylonia UK /ˌbæbɪˈləʊnɪə/US /ˌbæbɪˈloʊni.ə/ noun2 •(historical) An ancient empire and geographic region of Mesopotamia, existing from 1850 BCE to 539 BCE, based around the city of Babylon; at its maximum extent, covering parts of modern-day Iraq, Kuwait, Syria and Iran. •(historical) A geographic area equivalent to Mesopotamia, from the area of Babylon's empire at its maximum extent.