A firm, elastic substance resembling horn, taken from the upper jaw of the right whale; baleen. It is used as a stiffening in stays, fans, screens, and for various other purposes. See Baleen.
Whalebone is another name for baleen, the comb-like filters that Mysticeti whales use to filter food. Whalebone is made of keratin, not bone. This flexible, material was used as a plastic-like substance before plastics were invented.