The Collaborative International Dictionary of English v.0.48:

Mill \Mill\, n. [OE. mille, melle, mulle, milne, AS. myln,
   mylen; akin to D. molen, G. m["u]hle, OHG. mul[imac],
   mul[imac]n, Icel. mylna; all prob. from L. molina, fr. mola
   millstone; prop., that which grinds, akin to molere to grind,
   Goth. malan, G. mahlen, and to E. meal. [root]108. See Meal
   flour, and cf. Moline.]
   [1913 Webster]
   1. A machine for grinding or comminuting any substance, as
      grain, by rubbing and crushing it between two hard, rough,
      or indented surfaces; as, a gristmill, a coffee mill; a
      bone mill.
      [1913 Webster]

   2. A machine used for expelling the juice, sap, etc., from
      vegetable tissues by pressure, or by pressure in
      combination with a grinding, or cutting process; as, a
      cider mill; a cane mill.
      [1913 Webster]

   3. A machine for grinding and polishing; as, a lapidary mill.
      [1913 Webster]

   4. A common name for various machines which produce a
      manufactured product, or change the form of a raw material
      by the continuous repetition of some simple action; as, a
      sawmill; a stamping mill, etc.
      [1913 Webster]

   5. A building or collection of buildings with machinery by
      which the processes of manufacturing are carried on; as, a
      cotton mill; a powder mill; a rolling mill.
      [1913 Webster]

   6. (Die Sinking) A hardened steel roller having a design in
      relief, used for imprinting a reversed copy of the design
      in a softer metal, as copper.
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   7. (Mining)
      (a) An excavation in rock, transverse to the workings,
          from which material for filling is obtained.
      (b) A passage underground through which ore is shot.
          [1913 Webster]

   8. A milling cutter. See Illust. under Milling.
      [1913 Webster]

   9. A pugilistic encounter. [Cant] --R. D. Blackmore.
      [1913 Webster]

   10. Short for Treadmill.
       [Webster 1913 Suppl.]

   11. The raised or ridged edge or surface made in milling
       anything, as a coin or screw.
       [Webster 1913 Suppl.]

   12. A building or complex of buildings containing a mill[1]
       or other machinery to grind grains into flour.
       [PJC]

   Edge mill, Flint mill, etc. See under Edge, Flint,
      etc.

   Mill bar (Iron Works), a rough bar rolled or drawn directly
      from a bloom or puddle bar for conversion into merchant
      iron in the mill.

   Mill cinder, slag from a puddling furnace.

   Mill head, the head of water employed to turn the wheel of
      a mill.

   Mill pick, a pick for dressing millstones.

   Mill pond, a pond that supplies the water for a mill.

   Mill race, the canal in which water is conveyed to a mill
      wheel, or the current of water which drives the wheel.

   Mill tail, the water which flows from a mill wheel after
      turning it, or the channel in which the water flows.

   Mill tooth, a grinder or molar tooth.

   Mill wheel, the water wheel that drives the machinery of a
      mill.

   Gin mill, a tavern; a bar; a saloon; especially, a cheap or
      seedy establishment that serves liquor by the drink.

   Roller mill, a mill in which flour or meal is made by
      crushing grain between rollers.

   Stamp mill (Mining), a mill in which ore is crushed by
      stamps.

   To go through the mill, to experience the suffering or
      discipline necessary to bring one to a certain degree of
      knowledge or skill, or to a certain mental state.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stamp \Stamp\, n.
   1. The act of stamping, as with the foot.
      [1913 Webster]

   2. The which stamps; any instrument for making impressions on
      other bodies, as a die.
      [1913 Webster]

            'T is gold so pure
            It can not bear the stamp without alloy. --Dryden.
      [1913 Webster]

   3. The mark made by stamping; a mark imprinted; an
      impression.
      [1913 Webster]

            That sacred name gives ornament and grace,
            And, like his stamp, makes basest metals pass.
                                                  --Dryden.
      [1913 Webster]

   4. That which is marked; a thing stamped.
      [1913 Webster]

            Hanging a golden stamp about their necks. --Shak.
      [1913 Webster]

   5. [F. estampe, of German origin. See Stamp, v. t.] A
      picture cut in wood or metal, or made by impression; a
      cut; a plate. [Obs.]
      [1913 Webster]

            At Venice they put out very curious stamps of the
            several edifices which are most famous for their
            beauty and magnificence.              --Addison.
      [1913 Webster]

   6. An official mark set upon things chargeable with a duty or
      tax to government, as evidence that the duty or tax is
      paid; as, the stamp on a bill of exchange.
      [1913 Webster]

   7. Hence: A stamped or printed device, usually paper, issued
      by the government at a fixed price, and required by law to
      be affixed to, or stamped on, certain papers, as evidence
      that the government dues are paid; as, a postage stamp; a
      tax stamp; a receipt stamp, etc.
      [1913 Webster]

   8. An instrument for cutting out, or shaping, materials, as
      paper, leather, etc., by a downward pressure.
      [1913 Webster]

   9. A character or reputation, good or bad, fixed on anything
      as if by an imprinted mark; current value; authority; as,
      these persons have the stamp of dishonesty; the Scriptures
      bear the stamp of a divine origin.
      [1913 Webster]

            Of the same stamp is that which is obtruded on us,
            that an adamant suspends the attraction of the
            loadstone.                            --Sir T.
                                                  Browne.
      [1913 Webster]

   10. Make; cast; form; character; as, a man of the same stamp,
       or of a different stamp.
       [1913 Webster]

             A soldier of this season's stamp.    --Shak.
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   11. A kind of heavy hammer, or pestle, raised by water or
       steam power, for beating ores to powder; anything like a
       pestle, used for pounding or beating.
       [1913 Webster]

   12. A half-penny. [Obs.] --Beau. & Fl.
       [1913 Webster]

   13. pl. Money, esp. paper money. [Slang, U.S.]
       [1913 Webster]

   Stamp act, an act of the British Parliament [1765] imposing
      a duty on all paper, vellum, and parchment used in the
      American colonies, and declaring all writings on unstamped
      materials to be null and void.

   Stamp collector,
       (a) an officer who receives or collects stamp duties.
       (b) one who collects postage or other stamps, as an
           avocation or for investment; a philatelist.

   Stamp duty, a duty, or tax, imposed on paper and parchment
      used for certain writings, as deeds, conveyances, etc.,
      the evidence of the payment of the duty or tax being a
      stamp. [Eng.]

   Stamp hammer, a hammer, worked by power, which rises and
      falls vertically, like a stamp in a stamp mill.

   Stamp head, a heavy mass of metal, forming the head or
      lower end of a bar, which is lifted and let fall, in a
      stamp mill.

   Stamp mill (Mining), a mill in which ore is crushed with
      stamps; also, a machine for stamping ore.

   Stamp note, a stamped certificate from a customhouse
      officer, which allows goods to be received by the captain
      of a ship as freight. [Eng.]

   Stamp office, an office for the issue of stamps and the
      reception of stamp duties.
      [1913 Webster]

WordNet (r) 3.0 (2006):

stamp mill
    n 1: a mill in which ore is crushed with stamps [syn: stamp
         mill, stamping mill]