and yes, eta, it has the previous entry:

1. The game of backgammon. Now rare.
1730–46 Thomson Autumn 528 Or the quick dice, In thunder leaping from the box, awake The sounding gammon. a1734 North Lives (1826) I. 17 Whatever games were stirring, at places where he retired, as gammon, gleek, piquet, or even the merry main, he made one. 1800 E. Hervey Mourtray Fam. III. 81 Mr. Chowles was above, playing at gammon with mistress. 1826 J. Wilson Noct. Ambr. Wks. 1855 I. 124 The tailor at Yarrow ford dang ye all to bits baith at gammon and the dambrod.

2. A term at backgammon, denoting a degree of victory which scores equal to two ‘hits’ or ‘games’ (see quots. 1844, 1868).
1735 Dyche & Pardon, Gammon+a Term in a Play called Back Gammon. 1778 C. Jones Hoyle's Games Impr. 165 Six and Five, a Man to be carried from your Adversary's Ace Point, as far as he can go, for a Gammon or for a Hit. 1800 Gentl. Mag. I. 163 And by quick taking off, a gammon win. 1844 Backgammon 47 If one combatant have not removed his first man before the other has removed his last, ‘a gammon’ is lost and won, which is equivalent to two games. 1868 Boy's Own Bk. 590 If you can bear all your men away before your adversary has borne off one man, you win the gammon+But if your adversary is able to bear one of his men, before you have borne all yours, then your victory is reduced to a hit.

3. Comb., as gammon-board, -player.
1814 Monthly Mag. XXXVII. 47 It may be inferred that he too was a gammon-player. 1851 ‘Nimrod’ The Road 17 You'll have the gammon-board all to yourself.