elch

Old High German elch and Old English eolh both descend from Proto-Germanic *elhaz, meaning 'large deer.' The word traces further back to Proto-Indo-European *h1elki-, which may also have produced the Greek elkē and Latin alcēs. Pliny and Caesar both described the alcēs of the northern forests — a massive, ungainly animal with no knee joints (Caesar was wrong about that part).

In Europe, the word consistently meant the moose — Alces alces, the largest living deer, standing over six feet at the shoulder. German Elch, Swedish älg, and Norwegian elg all refer to this animal. When English settlers arrived in North America, they encountered two unfamiliar large deer: the moose and the wapiti.

The settlers called the moose 'moose,' borrowing an Algonquian word. Then they took their old word 'elk' and applied it to the wapiti — Cervus canadensis, a different species entirely. The result is a transatlantic confusion that persists today. Say 'elk' in London and people think moose. Say 'elk' in Montana and people think wapiti.

The renaming was not a mistake in the careless sense. English settlers used the words they had for the categories they perceived. The wapiti was the biggest deer they regularly encountered, so it got the word for 'big deer.' The moose was something else entirely — more strange than big. So it got a strange, foreign name. The logic was experiential, not zoological.