Source : Webster's Revised Unabridged Dictionary (1913)

Swirl \Swirl\, v. t. & i. [imp. & p. p. {Swirled}; p. pr. & vb.
   n. {Swirling}.] [Akin to Norw. svirla to whirl, freq. of
   sverra to whirl, Dan. svirre, G. schwirren to whiz, to buzz.
   [root]177. See {Swarm}, n.]
   To whirl, or cause to whirl, as in an eddy. ``The river
   swirled along.'' --C. Kingsley.

Source : WordNet®

swirling
     adj : moving or driven rapidly in a rotary or twisting motion; "a
           tornado's whirling winds"; "swirling currents" [syn: {whirling}]