iceberg

Etymology

Borrowed from Dutch ijsberg (compound of ijs (“ice”) + berg (“mountain”)), from Middle Dutch ijsberch. First used to describe a glacier as seen at a distance from a ship then used as a term to describe the floating chunks of ice broken off from such glaciers. Cognate to German Eisberg, Danish isbjerg, Norwegian isberg and Swedish isberg.

noun

1. (obsolete) The seaward end of a glacier. [18th–19th c.]
2. A huge mass of ocean-floating ice which has broken off a glacier or ice shelf [from 19th c.]
   The Titanic hit an iceberg and sank.
3. (US, slang) An aloof person. [from 19th c.]
4. (figurative, after an adjective) An impending disastrous event whose adverse effects are only beginning to show, in reference to one-tenth of the volume of an iceberg being visible above water.
   He has little to lose: at present he will go down in history, alongside George W. Bush, as a skipper who ignored the looming fiscal iceberg. 2013, “How Barack Obama can get at least some of his credibility back”, in The Economist