Where does “cauça” come from?

cauça (Occitan) comes from Vulgar Latin calcea, from Latin calceus, from Latin calx, from Ancient Greek χάλιξ — small stone, pebble; gravel, rubble.

Ancestry of “cauça”, step by step

Step	Language	Word	Meaning
1	Vulgar Latin	calcea	garment covering foot and leg
2	Latin	calceus	shoe
3	Latin	calx	limestone; chalk; the finish line
4	Ancient Greek	χάλιξ	small stone, pebble; gravel, rubble