WordWeb Online

1. Lacking in style or elegance
   "wearing unstylish clothes"
   - styleless
    
2. Not in accord with or not following current fashion
   "unstylish clothes"
   - unfashionable, daggy [Austral, NZ]

See also: antique, dated, démodé, dowdy, ex, fogyish, frumpish, frumpy, moss-grown, mossy, old, old-fashioned, old-hat, out, outmoded, passé, passée, prehistoric, rinky-dink [N. Amer], stick-in-the-mud, stodgy, vieux jeu