iceberg

Partial calque of Dutch ijsberg (being, by surface analysis, ijs (“ice”) +‎ berg (“mountain”)), from Middle Dutch ijsberch. A full calque might have been *icebarrow. Cognate with German Eisberg, Danish isbjerg, Norwegian isberg and Swedish isberg. First attested in 1774. Displaced native English island of ice and sea-hill.

First used to describe a glacier as seen at a distance from a ship, then as a term to describe the floating chunks of ice broken off of such a glacier. Figurative senses (e.g., tip of the iceberg) in allusion to most of an iceberg being unseen underwater.