The Collaborative International Dictionary of English v.0.48:

Swim \Swim\, v. i. [imp. Swamor Swum; p. p. Swum; p. pr. &
   vb. n. Swimming.] [AS. swimman; akin to D. zwemmen, OHG.
   swimman, G. schwimmen, Icel. svimma, Dan. sw["o]mme, Sw.
   simma. Cf. Sound an air bladder, a strait.]
   1. To be supported by water or other fluid; not to sink; to
      float; as, any substance will swim, whose specific gravity
      is less than that of the fluid in which it is immersed.
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   2. To move progressively in water by means of strokes with
      the hands and feet, or the fins or the tail.
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            Leap in with me into this angry flood,
            And swim to yonder point.             --Shak.
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   3. To be overflowed or drenched. --Ps. vi. 6.
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            Sudden the ditches swell, the meadows swim.
                                                  --Thomson.
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   4. Fig.: To be as if borne or floating in a fluid.
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            [They] now swim in joy.               --Milton.
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   5. To be filled with swimming animals. [Obs.]
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            [Streams] that swim full of small fishes. --Chaucer.
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The Collaborative International Dictionary of English v.0.48:

Swum \Swum\,
   imp. & p. p. of Swim.
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