(from the goddess Shach, reduplicated) is a term which occurs only in (Jeremiah 25:26; 51:41) where it is evidently used as a synonym for either Babylon or Babylonia.
bag of flax or linen ...
Hitchcock's Bible Names Dictionary
(Jer. 25:26), supposed to be equivalent to Babel (Babylon), according to a secret (cabalistic) mode ...
Easton's Bible Dictionary