Source : Webster's Revised Unabridged Dictionary (1913)

Demure \De*mure"\, a. [Perh. from OF. de murs (i. e., de bonnes
   murs of good manners); de of + murs, mours, meurs, mors, F.
   m?urs, fr. L. mores (sing. mos) manners, morals (see
   {Moral}); or more prob. fr. OF. me["u]r, F. m[^u]r mature,
   ripe (see {Mature}) in a phrase preceded by de, as de m[^u]re
   conduite of mature conduct.]
   1. Of sober or serious mien; composed and decorous in
      bearing; of modest look; staid; grave.

            Sober, steadfast, and demure.         --Milton.

            Nan was very much delighted in her demure way, and
            that delight showed itself in her face and in her
            clear bright eyes.                    --W. Black.

   2. Affectedly modest, decorous, or serious; making a show of
      gravity.

            A cat lay, and looked so demure, as if there had
            been neither life nor soul in her.    --L'Estrange.

            Miss Lizzy, I have no doubt, would be as demure and
            coquettish, as if ten winters more had gone over her
            head.                                 --Miss
                                                  Mitford.

Demure \De*mure"\, v. i.
   To look demurely. [Obs.] --Shak.

Source : WordNet®

demure
     adj : affectedly modest or shy especially in a playful or
           provocative way [syn: {coy}, {overmodest}]