1. One of the definite areas of the skin of a bird on which feathers grow

Derived forms: pterylae

• birken
• birl
• birle
• birling
• Birmingham
• Biro
• birr
• birretta
• birth
• birth canal
• birth certificate
• birth control
• birth control device
• birth control pill
• birth defect
• birth pangs
• birth prevention
• birth trauma
• birth-control campaigner
• birth-control reformer
• birthday
• birthday cake
• birthday card
• birthday gift
• birthday party