E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Shallow.
A weak-minded country justice, intended as a caricature of Sir Thomas Lucy, of Charlecote. He is described as one who had been a madcap in his youth, and still dotes on his wild tricks; he is withal a liar, a blockhead, and a rogue. (Shakespeare: Merry Wives of Windsor, and 2 Henry IV.)