pewter

Pewter comes from Middle English peutre, borrowed from Old French peautre, which traces to Vulgar Latin *peltrum, a word for the metal itself. Beyond that, its origin is uncertain.

The word has stayed close to its meaning throughout — it has always named this particular tin alloy, with no dramatic shift in sense recorded.

It's possibly related to spelter, another metal-alloy word, though the exact connection isn't certain.