E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A huge pewter measuring-pot, containing at least three English quarts. Readers of Waverley will remember (in chap. xi.) the Baron Bradwardines tappit-hen of claret from Bordeaux. To have a tappit-hen under the belt is to have swallowed three quarts
of claret. A hen and chickens means large and small drinking mugs or pewter pots. A tappit was served from the tap. (See JEROBOAM.)