What is "garnish bolt"

Garnish \Gar"nish\, n.

1. Something added for embellishment; decoration; ornament; also, dress; garments, especially such as are showy or decorated.

   So are you, sweet, Even in the lovely garnish of a boy.
   --Shak.

   Matter and figure they produce; For garnish this, and that for use.
   --Prior.

2. (Cookery) Something set round or upon a dish as an embellishment, such as parsley. See Garnish, v. t., 2.
   --Smart.

3. Fetters. [Cant]

4. A fee; specifically, in English jails, formerly an unauthorized fee demanded by the old prisoners of a newcomer. [Cant]
   --Fielding.

   Garnish bolt (Carp.), a bolt with a chamfered or faceted head.
   --Knight.

n. A bolt with a chamfered or faceted head.