1. [n]  a brushing or rustling sound
2. [adj]  (informal) elegant and fashionable; "classy clothes"; "a classy dame"; "a posh restaurant"; "a swish pastry shop on the Rue du Bac"- Julia Child
3. [v]  move with a swishing sound; "She swished into the room"
4. [v]  move with or make or cause to move with or make a whistling or hissing sound, as of liquids

SWISH is a 5 letter word that starts with S.

1. \Swish\, v. t. [From the sound. Cf. {Swash}.]
   1. To flourish, so as to make the sound swish. --Coleridge.
   
   2. To flog; to lash. [Slang] --Thackeray.
   
   

2. \Swish\, v. i.
   To dash; to swash.
   
   

3. \Swish\, n.
   1. A sound of quick movement, as of something whirled through
      the air. [Colloq.]
   
   2. (Naut.) Light driven spray. [Eng.]