Driveller

I can smash Shakspeare; I can prove Milton to be a driveller, or the contrary: but, for preference, take, as I have said, the abusive line.

Source: wiktionary

Think of the men whom I may call book-eaters! Dr. Parr was a driveller; Porson was a sort of learned pig who routed up truffles in the classic garden; poor Buckle became, through stress of books, a shallow thinker; Mezzofanti, with his sixty-four languages and dialects, was perilously like a fool; and more than one modern professor may be counted as nothing else but a vain, over-educated boor.

Source: wiktionary

[416:6] What intelligent Christian can believe that a minister, instructed by Paul or Peter, and filling one of the most important stations in the apostolic Church, was verily such an ignorant driveller?

Source: wiktionary

"All able men," adds Macaulay, "ridiculed him as a dunce, a driveller, a child who never knew his own mind an hour together; and yet he overreached them all."

Source: wiktionary