stucco

English borrowed stucco from Italian stucco, meaning a coating made of pulverized gypsum or plaster. That Italian word traces back to Lombardic stucki or *stucchi, meaning 'crust, fragment, piece,' which itself comes from Proto-Germanic *stukkiją, 'stump, piece,' rooted in the Proto-Indo-European *(s)tewg-, 'to shock, butt, impact.'

The word began as a plain description of a broken-off bit or crust, and narrowed over time into the specific Italian craft term for a smooth, moldable plaster coating, which English then adopted as-is.

It's a cousin of English stock and German Stück, both descending from the same Proto-Germanic word for 'piece' — so stucco and a 'piece' of something share a hidden ancestor.