whale·bone / ˈ(h)wālˌbōn/ • n. an elastic horny substance that grows in a series of thin parallel plates in the upper jaw of some whales and is used by them to strain plankton from the seawater. Also called baleen. ∎ strips of this substance, much used formerly as stays in corsets and dresses: [as adj.] a whalebone bodice. ∎ bone or ivory from a whale or walrus.