gammon

assimilated form of earlier gambon, borrowed from Anglo-French gamboun, jaumbeun, from gambe, jambe “hock of a horse, leg” + -on, diminutive or particularizing suffix, going back to Latin -ō, -ōn-, suffix of persons with a prominent feature — more at jamb

probably shortened from backgammon

derivative of ²gammon

derivative of ⁵gammon

argot word, earlier in sense “criminal accomplice who distracts a victim during a robbery,” of uncertain origin