The term 'BIRD's beak' can be broken down into three crossword solutions: BILL (4 letters), NIB (3 letters), and NEB (3 letters). A BIRD's beak is a curved, pointed organ at the front of a BIRD's head used for eating, grooming, and manipulating objects. The BILL is the most visible part of the beak and is typically used for feeding. The NIB is the tip of the beak, which is often sharp and used for pecking or probing. The NEB is the base of the beak, which is usually wider and more rounded than the NIB.