The Collaborative International Dictionary of English v.0.48:

Swell \Swell\, v. i. [imp. Swelled; p. p. Swelled or
   Swollen; p. pr. & vb. n. Swelling.] [AS. swellan; akin to
   D. zwellen, OS. & OHG. swellan, G. schwellen, Icel. svella,
   Sw. sv[aum]lla.]
   1. To grow larger; to dilate or extend the exterior surface
      or dimensions, by matter added within, or by expansion of
      the inclosed substance; as, the legs swell in dropsy; a
      bruised part swells; a bladder swells by inflation.
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   2. To increase in size or extent by any addition; to increase
      in volume or force; as, a river swells, and overflows its
      banks; sounds swell or diminish.
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   3. To rise or be driven into waves or billows; to heave; as,
      in tempest, the ocean swells into waves.
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   4. To be puffed up or bloated; as, to swell with pride.
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            You swell at the tartan, as the bull is said to do
            at scarlet.                           --Sir W.
                                                  Scott.
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   5. To be inflated; to belly; as, the sails swell.
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   6. To be turgid, bombastic, or extravagant; as, swelling
      words; a swelling style.
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   7. To protuberate; to bulge out; as, a cask swells in the
      middle.
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   8. To be elated; to rise arrogantly.
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            Your equal mind yet swells not into state. --Dryden.
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   9. To grow upon the view; to become larger; to expand.
      "Monarchs to behold the swelling scene!" --Shak.
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   10. To become larger in amount; as, many little debts added,
       swell to a great amount.
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   11. To act in a pompous, ostentatious, or arrogant manner; to
       strut; to look big.
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             Here he comes, swelling like a turkey cock. --Shak.
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The Collaborative International Dictionary of English v.0.48:

Swelling \Swell"ing\, n.
   1. The act of that which swells; as, the swelling of rivers
      in spring; the swelling of the breast with pride.
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            Rise to the swelling of the voiceless sea.
                                                  --Coleridge.
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   2. A protuberance; a prominence; especially (Med.), an
      unnatural prominence or protuberance; as, a scrofulous
      swelling.
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            The superficies of such plates are not even, but
            have many cavities and swellings.     --Sir I.
                                                  Newton.
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WordNet (r) 3.0 (2006):

swelling
    n 1: an abnormal protuberance or localized enlargement [syn:
         swelling, puffiness, lump]
    2: something that bulges out or is protuberant or projects from
       its surroundings; "the gun in his pocket made an obvious
       bulge"; "the hump of a camel"; "he stood on the rocky
       prominence"; "the occipital protuberance was well developed";
       "the bony excrescence between its horns" [syn: bulge,
       bump, hump, swelling, gibbosity, gibbousness,
       jut, prominence, protuberance, protrusion,
       extrusion, excrescence]
    3: the increase in volume of certain substances when they are
       heated (often accompanied by release of water) [syn:
       intumescence, intumescency, swelling]