British and American words diverge, sometimes confusingly. What Americans call 'French fries', the British call 'chips'. So what do the British call thin, crunchy potato slices in a bag?

The British word for thin, crunchy potato slices sold in a bag is "crisps," which is exactly what Americans call "chips." This creates a genuinely confusing double-swap: British "chips" are thick fried potato strips that Americans call "fries," while British "crisps" are the thin snack Americans call "chips."

"Fries" is the American word for the thick fried strips, which the British instead call "chips" — the opposite pairing from what an American might assume. "Chips" itself is the British word for those same thick fried strips, not the thin snack being asked about here.

This crossed terminology causes real confusion for travelers: an American ordering "chips" in a British pub will receive fries, while asking for "fries" may get a puzzled look, since the British snack aisle reserves "crisps" for the bagged, thin variety entirely.