Green’s Dictionary of Slang

a talkative person, esp. one who persuades one to act foolishly or against one’s will; by ext., a confidence trickster; also attrib.

1675		Head Art of Wheedling 171: Being an excellent Tongue-pad.
1676		A Newgate ex-prisoner A Warning for House-Keepers 7: A Tongue-Padder is one that hath a fine Tongue, a quick Wit, and can speak several Languages, he is one that seldom speaks truth but gives himself to Romancing. [...] You must know that this Tongue-Padder is one which is called a Setter, so that he Pads them in Town and his Confederates upon the Road, which for his information he receives his share.
1683		Fifteen Real Comforts of Matrimony 54: The cunning tongue-pad Slut […] undermines the very heart of a man.
c.1698		B.E. Dict. Canting Crew n.p.: tongue-pad, a smooth, Glib-tongued, insinuating Fellow.
1698		N. Ward London Spy I 10: Being a rare Tongue-Pad [...] he can out Flatter a Poet, out Huff a Bully, out Wrangle a Lawyer, out Cant a Puritan, [...] and out Lye the Devil.
1700		T. Brown Amusements Serious and Comical in Works (1744) III 87: The quack prov’d a sot, the bully a coward, and the tongue pad was silent.
1709		‘Phoebe Crackenthorpe’ Female Tatler (1992) (27) 64: At last the butchers, ale-house-keepers, and poulterer’s wives, people that abominate scolding, upon the advice of several eminent tongue-pads, hir’d six porters to attack her.
1725		New Canting Dict. [as cit. c.1698].
1734		C. Johnson Hist. of Highwaymen &c. 437: She was a tolerable handsome Woman, and a good Tongue Pad.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Tongue pad, a scold, or nimble-tongued person.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.