From 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. [1913 Webster]
2. To move progressively in water by means of strokes with the hands and feet, or the fins or the tail. [1913 Webster]
Leap in with me into this angry flood, And swim to yonder point. --Shak. [1913 Webster]
3. To be overflowed or drenched. --Ps. vi. 6. [1913 Webster]
Sudden the ditches swell, the meadows swim. --Thomson. [1913 Webster]
4. Fig.: To be as if borne or floating in a fluid. [1913 Webster]
[They] now swim in joy. --Milton. [1913 Webster]
5. To be filled with swimming animals. [Obs.] [1913 Webster]
[Streams] that swim full of small fishes. --Chaucer. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Swam \Swam\, imp. of Swim. [1913 Webster]