[W/K] :: pileus

  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]

  pileus
       n : a fruiting structure resembling an umbrella that forms the
           top of a stalked fleshy fungus such as a mushroom [syn: cap]
       [also: pilei (pl)]