The Collaborative International Dictionary of English v.0.48:

Stylish \Styl"ish\, a.
   Having style or artistic quality; given to, or fond of, the
   display of style; highly fashionable; modish; as, a stylish
   dress, house, manner. -- Styl"ish*ly, adv. --
   Styl"ish*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stylish
    adj 1: having elegance or taste or refinement in manners or
           dress; "a little less posh but every bit as stylish as
           Lord Peter Wimsey"; "the stylish resort of Gstadd" [syn:
           stylish, fashionable] [ant: styleless, unstylish]
    2: being or in accordance with current social fashions;
       "fashionable clothing"; "the fashionable side of town"; "a
       fashionable cafe" [syn: fashionable, stylish] [ant:
       unfashionable, unstylish]

Moby Thesaurus II by Grady Ward, 1.0:

109 Moby Thesaurus words for "stylish":
   Daedalian, a la mode, adept, adroit, apt, artistic, authoritative,
   bravura, brilliant, chic, chichi, classy, clean, clever,
   coordinated, crack, crackerjack, cunning, cute, daedal, dashing,
   deft, dexterous, dextrous, diplomatic, doggy, dressed to advantage,
   dressed up, elegant, en grande tenue, endimanche, excellent,
   exclusive, expert, fancy, fashionable, good, goodish, graceful,
   gussied up, handy, in, in fashion, in full dress, in full feather,
   in high feather, in tails, in the mode, ingenious, magisterial,
   masterful, masterly, modern, modish, natty, neat, new,
   new-fashioned, newfangled, no mean, ostentatious, politic, posh,
   pretentious, professional, proficient, quick, quite some, rakish,
   ready, resourceful, ritzy, sassy, sharp, showy, skillful, sleek,
   slick, slicked up, smart, snappy, snazzy, soigne, soignee, some,
   spiffy, spruce, statesmanlike, swagger, swank, swanky, swell,
   swish, tactful, the compleat, the complete, tony, trendy, trig,
   ultrafashionable, virtuoso, vogue, voguish, well turned-out,
   well-done, well-dressed, with it, with-it, workmanlike