Where does “calceo” come from?

calceo (Latin) comes from Latin calceus, from Latin calx, from Ancient Greek χάλιξ — small stone, pebble; gravel, rubble.

Ancestry of “calceo”, step by step

Step	Language	Word	Meaning
1	Latin	calceus	shoe
2	Latin	calx	limestone; chalk; the finish line
3	Ancient Greek	χάλιξ	small stone, pebble; gravel, rubble