the.com/whalebone

means A strong, flexible material taken from the filter plates in certain whales' mouths, once widely used to stiffen corsets, hoops, brushes, and other everyday objects.

from The word is just 'whale' plus 'bone,' bolted together in English once sailors and merchants started hauling baleen home and treating it like a construction material. It's not etymologically tricky — the trickery is in the thing itself: baleen isn't bone at all but keratin, the same stuff as hair and fingernails, growing in long plates from a whale's upper jaw. People named it by what it resembled and how it was used (stiff, carvable, bendable — bonelike) rather than by what it biologically was, and the misnomer simply outlived the correction.