French path in South Gironde at first slippery (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

CHEMIN (French word for a path, as in chemin de fer = iron path = railway), in the first letters of S [outh] G [ironde]. Scheming = slippery = descriptive of a dishonest or untrustworthy person.