The Collaborative International Dictionary of English v.0.48:

Flint \Flint\, n. [AS. flint, akin to Sw. flinta, Dan. flint;
   cf. OHG. flins flint, G. flinte gun (cf. E. flintlock), perh.
   akin to Gr. ? brick. Cf. Plinth.]
   1. (Min.) A massive, somewhat impure variety of quartz, in
      color usually of a gray to brown or nearly black, breaking
      with a conchoidal fracture and sharp edge. It is very
      hard, and strikes fire with steel.
      [1913 Webster]

   2. A piece of flint for striking fire; -- formerly much used,
      esp. in the hammers of gun locks.
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   3. Anything extremely hard, unimpressible, and unyielding,
      like flint. "A heart of flint." --Spenser.
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   Flint age. (Geol.) Same as Stone age, under Stone.

   Flint brick, a fire made principially of powdered silex.

   Flint glass. See in the Vocabulary.

   Flint implements (Arch[ae]ol.), tools, etc., employed by
      men before the use of metals, such as axes, arrows,
      spears, knives, wedges, etc., which were commonly made of
      flint, but also of granite, jade, jasper, and other hard
      stones.

   Flint mill.
      (a) (Pottery) A mill in which flints are ground.
      (b) (Mining) An obsolete appliance for lighting the miner
          at his work, in which flints on a revolving wheel were
          made to produce a shower of sparks, which gave light,
          but did not inflame the fire damp. --Knight.

   Flint stone, a hard, siliceous stone; a flint.

   Flint wall, a kind of wall, common in England, on the face
      of which are exposed the black surfaces of broken flints
      set in the mortar, with quions of masonry.

   Liquor of flints, a solution of silica, or flints, in
      potash.

   To skin a flint, to be capable of, or guilty of, any
      expedient or any meanness for making money. [Colloq.]
      [1913 Webster]

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.
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   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.
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   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.
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   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.
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   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]