The Collaborative International Dictionary of English v.0.48:

Swell \Swell\, n.
   1. The act of swelling.
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   2. Gradual increase. Specifically:
      (a) Increase or augmentation in bulk; protuberance.
      (b) Increase in height; elevation; rise.
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                Little River affords navigation during a swell
                to within three miles of the Miami. --Jefferson.
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      (c) Increase of force, intensity, or volume of sound.
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                Music arose with its voluptuous swell. --Byron.
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      (d) Increase of power in style, or of rhetorical force.
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                The swell and subsidence of his periods.
                                                  --Landor.
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   3. A gradual ascent, or rounded elevation, of land; as, an
      extensive plain abounding with little swells.
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   4. A wave, or billow; especially, a succession of large
      waves; the roll of the sea after a storm; as, a heavy
      swell sets into the harbor.
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            The swell
            Of the long waves that roll in yonder bay.
                                                  --Tennyson.
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            The gigantic swells and billows of the snow.
                                                  --Hawthorne.
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   5. (Mus.) A gradual increase and decrease of the volume of
      sound; the crescendo and diminuendo combined; -- generally
      indicated by the sign.
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   6. A showy, dashing person; a dandy. [Slang]
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   Ground swell. See under Ground.

   Organ swell (Mus.), a certain number of pipes inclosed in a
      box, the uncovering of which by means of a pedal produces
      increased sound.

   Swell shark (Zool.), a small shark (Scyllium ventricosum)
      of the west coast of North America, which takes in air
      when caught, and swells up like a swellfish.
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