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.