fan-crest

from The Century Dictionary.

• noun A form of crest common in the middle ages at different periods, as in the reign of Richard I. of England, whose second great seal shows this crest, and again at the end of the thirteenth century, when it assumed the shape of a fan or screen with radiating ribs, attached to the helm at a single point.
• noun In ornithology, a large longitudinal crest which opens and closes somewhat like a fan. The crests of the hoopoe and cockatoo are examples.