The Collaborative International Dictionary of English v.0.48:

Modish \Mod"ish\, a.
   According to the mode, or customary manner; conformed to the
   fashion; fashionable; hence, conventional; as, a modish
   dress; a modish feast. --Dryden. "Modish forms of address."
   --Barrow.
   [1913 Webster] -- Mod"ish*ly, adv. -- Mod"ish*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

modishness
    n 1: elegance by virtue of being fashionable [syn: chic,
         chicness, chichi, modishness, smartness,
         stylishness, swank, last word]