Source : Webster's Revised Unabridged Dictionary (1913)

Swim \Swim\, v. i. [imp. {Swam}or {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.

   2. To move progressively in water by means of strokes with
      the hands and feet, or the fins or the tail.

            Leap in with me into this angry flood, And swim to
            yonder point.                         --Shak.

   3. To be overflowed or drenched. --Ps. vi. 6.

            Sudden the ditches swell, the meadows swim.
                                                  --Thomson.

   4. Fig.: To be as if borne or floating in a fluid.

            [They] now swim in joy.               --Milton.

   5. To be filled with swimming animals. [Obs.]

            [Streams] that swim full of small fishes. --Chaucer.

Swam \Swam\,
   imp. of {Swim}.

Source : WordNet®

swim
     n : the act of swimming [syn: {swimming}]
     [also: {swum}, {swimming}, {swam}]

swim
     v 1: travel through water; "We had to swim for 20 minutes to
          reach the shore"; "a big fish was swimming in the tank"
     2: be afloat; stay on a liquid surface; not sink [syn: {float}]
        [ant: {sink}]
     [also: {swum}, {swimming}, {swam}]

swam
     See {swim}