NOUN (2)

1. something resembling the head of a nail that is used as an ornamental device;

2. flattened boss on the end of nail opposite to the point;

The Collaborative International Dictionary of English v.0.48:

Nail-headed \Nail"-head`ed\, a.
   Having a head like that of a nail; formed so as to resemble
   the head of a nail.
   [1913 Webster]

   Nail-headed characters, arrowheaded or cuneiform
      characters. See under Arrowheaded.

   Nail-headed molding (Arch.), an ornament consisting of a
      series of low four-sided pyramids resembling the heads of
      large nails; -- called also nail-head molding, or
      nail-head. It is the same as the simplest form of
      dogtooth. See Dogtooth.
      [1913 Webster]