So

Easton's Bible Dictionary (1897)

(Nubian, Sabako), an Ethiopian king who brought Egypt under his sway. He was bribed by Hoshea to help him against the Assyrian monarch Shalmaneser (2 Kings 17:4). This was a return to the policy that had been successful in the reign of Jeroboam I.

Smith's Bible Dictionary (1863)

“So, king of Egypt,” is once mentioned in the Bible— (2 Kings 17:4) So has been identified by different writers with the first and second kings of the Ethiopian twenty-fifth dynasty, called by Manetho, Sabakon (Shebek) and Sebichos (Shebetek).

Hitchcock's Bible Names Dictionary (1869)

a measure for grain; vail

Public domain dictionaries.