Easton's Bible Dictionary (1897)
Chief of the princes, the name given to the chief cup-bearer or the vizier of the Assyrian court; one of Sennacherib’s messengers to Hezekiah. See the speech he delivered, in the Hebrew language, in the hearing of all the people, as he stood near the wall on the north side of the city (2 Kings 18:17-37). He and the other envoys returned to their master and reported that Hezekiah and his people were obdurate, and would not submit.
Smith's Bible Dictionary (1863)
(chief cupbearer), (2 Kings 19:1; Isaiah 36:1; Isaiah 37:1) ... one of the officers of the king of Assyria sent against Jerusalem in the reign of Hezekiah. ) The English version takes Rabshakeh as the name of a person; but it is more probably the name of the office which he held at the court, that of chief cupbearer.
Hastings' Dictionary of the Bible (1898)
RAB'SHAKEH seems to be the name, not of a person, but of an officer - the chief butler or cupbearer - who was sent with Rab-saris, the chief of the eunuchs, and Tartan, messengers of the king of Assyria, to Hezekiah, summoning him, in the most indecent and blasphemous manner, to surrender his capital. 2 Kgs 18:17-37.