n. [ F. baleine whale and whalebone, L. balaena a whale; cf. Gr. fa`laina. ] (Zool. & Com.) Plates or blades of “whalebone, ” from two to twelve feet long, and sometimes a foot wide, which in certain whales (Balænoidea) are attached side by side along the upper jaw, and form a fringelike sieve by which the food is retained in the mouth. [ 1913 Webster ]
n. The more primitive parts of the brain phylogenetically; it includes most structures other than the cerebral cortex. Syn. -- paleoencephalon, palaeoencephalon. [ WordNet 1.5 ]