The crossword solution for the term BEAK OF A BIRD is NEB. A bird's beak, also known as a bill, is an external body part that is used for eating, grooming, and manipulating objects. It is made of keratin, the same material that makes up human fingernails. The shape and size of a bird's beak is adapted to its diet and lifestyle. For example, a hummingbird has a long, thin beak for reaching nectar in flowers, while a woodpecker has a chisel-like beak for drilling into trees.