kelp

The origin is genuinely uncertain. One theory traces kelp to Old English *cylp, possibly from a Proto-Germanic word meaning "lump" or "boll," referring to the air-filled sacs on seaweeds like bladderwrack. A separate, unrelated theory derives it from Old Norse kilpr, meaning the handle or loop of a vessel.

The facts don't support tracing a clear shift in meaning — the word's early form and even its root language are disputed, so this entry stays close to the two competing origin stories rather than a single line of development.

If the "lump" theory holds, kelp would be distantly related to words like Low German Kulp ("lump") and Swedish kulp ("stout person") — all pointing to the idea of something round and swollen.