1. [late 17C–early 18C] to cheat (at a game).
2. [mid-18C] (UK Und.) to help.
3. [late 18C] to talk criminal slang.
4. [late 18C+] to deceive, to fool, to talk humbug, to pretend.
5. [19C] to persuade.
6. [mid-19C] to tease amicably.
7. to flatter.
[early 19C] (UK Und.) of a beggar, to pose as ill.
[early 19C] to pretend to be drunk.
[early 19C] ‘When a man is without a shirt, and is buttoned up close to his neck, with merely a handkerchief round it, to make an appearance of cleanliness, it is termed, “gammoning the draper”’ (Egan, Life in London, 1821).
[late 18C–early 19C] (UK Und.) to gain an acquittal in court; the implication is that the defendant has managed to fool the jurymen.