Baleen

Ba‐leen″ (bȧ‐lēn″), n. [F. baleine whale and whalebone, L. balaena a whale; cf. Gr. φάλαινα.] (Zoöl. & 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.