The Spanish arena means “sand” or “dirt” while the English arena means, well, arena (something similar to a stadium). Nothing to do with sand!
Or so it seems…
Interestingly, both come from the same root: the Latin harena which meant “a place to combat, usually a sandy place” but came from an older, Etruscan word meaning, “a sandy place”. From the older meaning we get the Spanish sand, but from the Roman variation — apparently, the Romans often fought on sand! — we get the newer, English meaning.
