Bible Dictionaries
Sheshach

Fausset's Bible Dictionary

Jeremiah 25:26; Jeremiah 51:41; i.e. Babylon, from their goddess Shach reduplicated, as they named Misael Meshach. SHACE was the designation of a Babylonian feast to Shach, of five days' duration, during which unbridled license prevailed as at the Roman saturnalia. Slaves ruled their master, and one called zogan in each house in royal garments ruled the rest (Jeremiah 51:39; Jeremiah 51:57; Isaiah 21:5). Cyrus during it took Babylon; thus Jeremiah prophesies the concomitants of the capture. The Kabalistic system (Αthbash , "the first Hebrew letter being expressed by the last, the second by the last but one," etc.) would make Sheshach answer to Βabel . But in Jeremiah 51:41 concealment cannot have been Jeremiah's object, for he mentions "Babylon" (Jeremiah 51:42). It is not likely the Kabala was as yet invented.

Bibliography Information
Fausset, Andrew R. Entry for 'Sheshach'. Fausset's Bible Dictionary. https://www.studylight.org/​dictionaries/​eng/​fbd/​s/sheshach.html. 1949.