waltz

From German Walzer, itself from walzen, meaning 'to dance,' which traces back through Old High German walzan ('to turn') and Proto-Germanic *walt- to the Proto-Indo-European root *welH-, 'to turn.'

The word started as a plain description of turning or rotating, then narrowed in German to mean dancing itself, before settling in English as the name for this specific turning dance.

It's a doublet of valse, meaning both words descend from the same root but arrived in English by different paths.