Definition of baleen

• n. - Plates or blades of "whalebone," from two to twelve feet long, and sometimes a foot wide, which in certain whales (Balaenoidea) are attached side by side along the upper jaw, and form a fringelike sieve by which the food is retained in the mouth.
• n. - Plates or blades of "whalebone," from two to twelve feet long, and sometimes a foot wide, which in certain whales (Balaenoidea) are attached side by side along the upper jaw, and form a fringelike sieve by which the food is retained in the mouth.