The Collaborative International Dictionary of English v.0.48:

Tasteful \Taste"ful\ (t[=a]st"f[.u]l), a.
   1. Having a high relish; savory. "Tasteful herbs." --Pope.
      [1913 Webster]

   2. Having or exhibiting good taste; in accordance with good
      taste; tasty; as, a tasteful drapery.
      [1913 Webster] -- Taste"ful*ly, adv. --
      Taste"ful*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

tastefulness
    n 1: elegance indicated by good taste [ant: tastelessness]