出典:Wiktionary
Origin obscure and uncertain. Possibly from the English dialectal (North Midlands) adjective game (“lame”), Welsh cam (“crooked”), or from Irish cam (“bent”), by way of Shelta. Compare also Old Occitan gambi (“lame, limping”), related to Old Occitan gamba (“leg”) (see also French jambe (“leg”), English gam (“leg”)).
gammy (comparative gammier, superlative gammiest)
Abbreviation.
Unclear.