noun (n)

• the shape of something rotating rapidly(noun.shape)

  Synonym:
  convolution, swirl, whirl
  

  source: wordnet30
• a powerful circular current of water (usually the result of conflicting tides)(noun.event)

  Synonym:
  maelstrom, whirlpool
  

  source: wordnet30
• A mass of fluid, especially of a liquid, having a whirling or circular motion tending to form a cavity or vacuum in the center of the circle, and to draw in towards the center bodies subject to its action; the form assumed by a fluid in such motion; a whirlpool; an eddy.(noun)

  source: webster1913