top piece

noun3

1. •
   (US, informal) Something worn on the head; a hat, a wig or toupee.

   • The Mayor took himself up in the lift, quite naked of course, except for his top-piece and neckpiece with his two shopping-bags […]. — 1973
2. •
   The part of the heel on a shoe or boot that comes into contact with the ground.

   • Then pare the top piece to the size and form you intend it to be; but that you should always do before the heel is sewed, for now you are confined to the channel. — 1834
3. •
   The head or brain.