The Collaborative International Dictionary of English v.0.48:

Swish \Swish\, v. t. [From the sound. Cf. Swash.]
   1. To flourish, so as to make the sound swish. --Coleridge.
      [1913 Webster]

   2. To flog; to lash. [Slang] --Thackeray.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swish \Swish\, v. i.
   To dash; to swash.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swish \Swish\, n.
   1. A sound of quick movement, as of something whirled through
      the air. [Colloq.]
      [1913 Webster]

   2. (Naut.) Light driven spray. [Eng.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

swish
    adj 1: elegant and fashionable; "classy clothes"; "a classy
           dame"; "a posh restaurant"; "a swish pastry shop on the
           Rue du Bac"- Julia Child [syn: classy, posh, swish]
    n 1: a brushing or rustling sound
    v 1: move with or cause to move with a whistling or hissing
         sound; "The bubbles swoshed around in the glass"; "The
         curtain swooshed open" [syn: lap, swish, swosh,
         swoosh]