Ounce (ouns), n. [F. once, fr. L. uncia a twelfth, the twelfth part of a pound or of a foot: cf. Gr. 'ogkos bulk, mass, atom. Cf. 2d Inch, Oke.] 1. A 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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&hand_; 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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