pilei

Webster's Dictionary (GCIDE)

Pileus \Pi"le*us\, n.; pl. Pilei. [L., a felt cap.]

1.(Rom. Antiq.) A kind of skull cap of felt. [1913 Webster]

2.(Bot.) The expanded upper portion of many of the fungi. See Mushroom. [1913 Webster]

3.(Zool.) The top of the head of a bird, from the bill to the nape. [1913 Webster]