The Collaborative International Dictionary of English v.0.48:

Milling \Mill"ing\, n.
   The act or employment of grinding or passing through a mill;
   the process of fulling; the process of making a raised or
   intented edge upon coin, etc.; the process of dressing
   surfaces of various shapes with rotary cutters. See Mill.
   [1913 Webster]

   High milling, milling in which grain is reduced to flour by
      a succession of crackings, or of slight and partial
      crushings, alternately with sifting and sorting the
      product.

   Low milling, milling in which the reduction is effected in
      a single crushing or grinding.

   Milling cutter, a fluted, sharp-edged rotary cutter for
      dressing surfaces, as of metal, of various shapes.

   Milling machine, a machine tool for dressing surfaces by
      rotary cutters.

   Milling tool, a roller with indented edge or surface, for
      producing like indentations in metal by rolling pressure,
      as in turning; a knurling tool; a milling cutter.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mill \Mill\ (m[i^]l), v. t. [imp. & p. p. Milled (m[i^]ld); p.
   pr. & vb. n. Milling.] [See Mill, n., and cf. Muller.]
   [1913 Webster]
   1. To reduce to fine particles, or to small pieces, in a
      mill; to grind; to comminute.
      [1913 Webster]

   2. To shape, finish, or transform by passing through a
      machine; specifically, to shape or dress, as metal, by
      means of a rotary cutter.
      [1913 Webster]

   3. To make a raised border around the edges of, or to cut
      fine grooves or indentations across the edges of, as of a
      coin, or a screw head; also, to stamp in a coining press;
      to coin.
      [1913 Webster]

   4. To pass through a fulling mill; to full, as cloth.
      [1913 Webster]

   5. To beat with the fists. [Cant] --Thackeray.
      [1913 Webster]

   6. To roll into bars, as steel.
      [1913 Webster]

   To mill chocolate, to make it frothy, as by churning.
      [1913 Webster]

WordNet (r) 3.0 (2006):

milling
    n 1: corrugated edge of a coin

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "milling":
   architecture, assembly, building, casting, composition,
   construction, conversion, crafting, craftsmanship, creation,
   cultivation, devising, elaboration, erection, extraction,
   fabrication, fashioning, formation, forming, formulation, framing,
   growing, handicraft, handiwork, harvesting, machining, making,
   manufacture, manufacturing, mining, molding, prefabrication,
   preparation, processing, producing, raising, refining, shaping,
   smelting, workmanship