walnut

From Middle English walnote, from Old English wealhhnutu, literally "foreign nut," from Proto-Germanic *walhahnuts, meaning "foreigner-nut."

The name preserved a judgment of origin rather than a description of the nut itself — it simply marked the thing as coming from elsewhere.

It's cognate with Dutch walnoot, German Walnuss, Swedish valnöt, and Icelandic valhneta, all built from the same Germanic root. It also shares its logic with Welsh onion, where "Welsh" likewise just meant "foreign."