Chaldees
    or Chaldeans, the inhabitants of the country of which Babylon
    was the capital. They were so called till the time of the
    Captivity (2 Kings 25; Isa. 13:19; 23:13), when, particularly in
    the Book of Daniel (5:30; 9:1), the name began to be used with
    special reference to a class of learned men ranked with the
    magicians and astronomers. These men cultivated the ancient
    Cushite language of the original inhabitants of the land, for
    they had a "learning" and a "tongue" (1:4) of their own. The
    common language of the country at that time had become
    assimilated to the Semitic dialect, especially through the
    influence of the Assyrians, and was the language that was used
    for all civil purposes. The Chaldeans were the learned class,
    interesting themselves in science and religion, which consisted,
    like that of the ancient Arabians and Syrians, in the worship of
    the heavenly bodies. There are representations of this priestly
    class, of magi and diviners, on the walls of the Assyrian
    palaces.