Green’s Dictionary of Slang

duplicitous.

1835		New Sporting Mag. May 14: I feared he might want it for the purpose of inflicting summary punishment on his ‘gammonacious’ friend of the previous evening.
1838		R.S. Surtees Jorrocks Jaunts (1874) 119: There was nothing gammonacious, as I calls it, about his toggery. [Ibid.] 121: Never was so done in all my life—a gammonacious fellow!

persuasive nonsense.

1874

‘Old Calabar’ Won in a Canter II 268: ‘[G]entlemen riders — none of yer half and half swells, but the genuine article who are above bribery, buttered gammon and don’t bet’.

1. criminal cant.

1781		G. Parker View of Society II 49: After the Rider has stood all this Gammon and Patter, he asks the hostler what he shall give to boot betwixt their horses.
1789		G. Parker Life’s Painter 150: Gammon and patter is the language of cant; when one of them speaks well, another says he gammons well, or he has got a great deal of rum patter.

2. any form of jargon or ‘professional slang’.

c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Gamon and Patter. Common place talk of any profession; as the Gammon and Patter of a Horse Dealer, &c.
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (3rd edn) n.p.:
1801		‘Modern Dict.’ in Sporting Mag. May XVIII 100/2: Gammon and Patter.-Common place talk of horse-dealers, &c.
1811		Lex. Balatronicum.
1822		Sporting Mag. May 70/1: Our lucubrations are most especially intended for the benefit of those provincials who are not sufficiently awake to the gammon and patter of the long town.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

3. verbose chatter.

1789		G. Parker Life’s Painter 143: What’s all this gammon and patter about?
1822		Blighted Ambition III 111: In all the gammon and patter between a younker ycleped Weston and me, about bub and grub [etc.].
1912		E.H. Fowler Life of Henry Hartley Fowler 654: With cheap gammon and patter about the evils of party, I think he had no sort of sympathy.

nonsense, rubbish, humbug.

1808		G. Colman Yngr ‘Heigho! says Thimble’ in Killing No Murder n.p.: With her roley, poley, / Gammon and spinnage; / Heigho! says Thimble.
1825		‘Sheep’s Eyes’ in Universal Songster I 13/2: Gammon and spinage, quoth Neddy.
1838		Dickens Oliver Twist (1966) 134: ‘Toor rul lol loo, gammon and spinnage, the frog he wouldn’t, and high cockolorum,’ said the Dodger.
1853		Dickens Bleak House (1991) 200: Death, Cunning, Folly, Words, Wigs, Rags, Sheepskin, Plunder, Precedent, Jargon, Gammon, and Spinach.
1860		R.S. Surtees Plain or Ringlets? (1926) 132: ‘Sivin and four’s elivin and sivinty-sivin’s eighty-eight, on the gammon and spinach tack’.
1892		in Punch 15 Oct. 170: BULL’s fame, in a boat, seems all gammon and spinach.
1910		‘O. Henry’ ‘A Ramble in Aphasia’ in Strictly Business (1915) 136: Oh, gammon and jalap!
1977		‘John le Carré’ Honourable Schoolboy 525: ‘Gammon and spinach!’ Connie stormed.

to wheedle.

1853		F.C. Adams Manuel Pereira cap. xi: The Captain [...] wanted to come the gammon game with him, and pass him for a white man; but sure he couldn't come that game over meself.
1866		A. Sketchley Brown Papers 95: She was up for the murder of her infant, as was six months old, only she come the gammon that strong [...] the jury let her off.

(UK und.) to over-rule, to out-talk (by the use of professional jargon).

c.1790

New Flash Song [broadside ballad] We gammon’d hard our lives to saves / And to the old beak gossip gave / But our prosecutor was so hard / [...] / We ere gammon-patter’d, to Newgate sent.

to recount too many anecdotes.

1902

H. Baumann Londinismen (2nd edn).

to concoct a story, to ‘tell the tale’.

1821		‘An Amateur’ Real Life in London II 88: He can pitch the gammon to the wine merchant, and induce him to stand the nonsense.
1849		Paul Pry 26 Mar. 3/3: Paul Advises [...] The Chubby auctioneer not to pitch too much gammon when selling the Hale man’s horses, &c.

1. to accept that one has been tricked.

1812

Spirit of Irish Wit 100: The wits found they were completely had [...] and therefore agreed [...] to stand the gammon.

2. (UK Und.) to withstand interrogation.

1818

W. Perry London Guide 79: He was conveyed to the watch house in Bunhill Row. Here he [...] stood the gammon as well as I ever saw.

very good, incontrovertibly.

1856

Mons. Merlin 18 Oct. 6/2: A crowded ball-room a ‘first-rate,’ ‘tip-top,’ ‘no-mistake,’ ‘stow-aIl-gammon,’ kind of ‘turn-out’ in a word (and that the chief in the vocabulary) quite the Stilton.

to ‘shoot a line’, to attempt seduction.

c.1864

‘She’s Gentle as a Tiger’ in Rakish Rhymer (1917) 41: But when the gammon to her I tip, / While out upon the spree, / She blushes like the scarlet flower.

(UK Und.) aware, knowing, capable.

1805		W. Collins Memoirs of a Picture I 223: Damme, he was up to gammon, as sharp as any of us.
1830		Lytton Paul Clifford III 244: Harry spoke up for you, and said as ’ow though you had just gone on the town, you was already prime up to gammon.
1846		D. Corcoran Picking from N.O. Picayune 78: The lapidary, who is a regularly initiated member of the Sawyer’s Company, was at once ‘up to gammon’.