A helicopter, an aircraft that derives its lift from rotating blades. The rescue team arrived quickly in a whirlybird to airlift the injured hikers.
A winged seed (samara) of a maple or similar tree that spins as it falls to the ground. The children chased the whirlybirds that fluttered down from the old maple.
(Australia, informal) A roof-mounted ventilator with spinning vanes used to extract hot air from a building. They installed two whirlybirds on the roof to keep the house cooler in summer.