Ounce \Ounce\ (ouns), n. [F. once, fr. L. uncia a twelfth, the
   twelfth part of a pound or of a foot: cf. Gr. 'o`gkos bulk,
   mass, atom. Cf. 2d Inch, Oke.]
   1. A unit of mass or weight, the sixteenth part of a pound
      avoirdupois, and containing 28.35 grams or 4371/2 grains.
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   2. (Troy Weight) The twelfth part of a troy pound; one troy
      ounce weighs 31.103486 grams, 8 drams, or 480 grains.
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   Note: The troy ounce contains twenty pennyweights, each of
         twenty-four grains, or, in all, 480 grains, and is the
         twelfth part of the troy pound. The troy ounce is also
         a weight in apothecaries' weight. [Troy ounce is
         sometimes written as one word, troyounce.]
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   3. Fig.: A small portion; a bit. [Obs.]
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            By ounces hung his locks that he had. --Chaucer.
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   Fluid ounce. See under Fluid, n.
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Troyounce \Troy"ounce\, n.
   See Troy ounce, under Troy weight, above, and under
   Ounce.
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