E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Jack of Dover.
A stockfish, “hake salted and dried.” The Latin for a hake is merlucius, and lucius is a jack or pike. Mer, of course, means the sea, and Dover, the chief Cinque Port, is used as a synonym. Also refuse wine collected into a bottle and sold for fresh wine. “To do-over again.” (See DOVER.)
