gam·mon¹ / ˈgamən/ • n. ham that has been cured or smoked like bacon. ∎  the bottom piece of a side of bacon, including a hind leg.gam·mon² • n. a victory in backgammon (carrying a double score) in which the winner removes all their pieces before the loser has removed any.• v. [tr.] defeat (a backgammon opponent) in such a way.gam·mon³ inf., dated, chiefly Brit. • n. nonsense; rubbish.• v. [tr.] hoax or deceive (someone).

gammon nonsense, rubbish. First recorded in the early 18th century; the origin is uncertain, but the term was first used in criminals' slang in give gammon ‘give cover to (a pickpocket)’ and keep in gammon ‘distract (a victim) for a pickpocket’.
gammon and spinach ‘nonsense, humbug’; with a pun on gammon ‘bacon, ham’. The words gammon and spinach are part of the refrain to the song ‘A frog he would a-wooing go’, and the term is used by Dickens: Miss Mowcher in David Copperfield (1850) says, ‘What a world of gammon and spinnage it is, though, ain't it!’.

gammon Hind legs of pig, cured while still part of the carcass. Ham is the same part of the pig but is cured after removal from the carcass. See also bacon; pork.

gammon2 lashing of the bowsprit. XVII. perh. identical with prec., the allusion being to the tying up of a gammon or ham.

gammon1 †ham XV; joint of bacon XVI. — ONF. gambon (modF. jambon) ham, f. gambe leg.