pileum

noun

pi·​le·​um ˈpī-lē-əm 

plural pilea ˈpī-lē-ə 

: the top of the head of a bird from the bill to the nape

Word History

Etymology

borrowed from Latin pilleus, pīleus, pilleum, pīleum "felt cap" — more at pileus

First Known Use

1874, in the meaning defined above