Source : Webster's Revised Unabridged Dictionary (1913)

Tasteless \Taste"less\, a.
   1. Having no taste; insipid; flat; as, tasteless fruit.

   2. Destitute of the sense of taste; or of good taste; as, a
      tasteless age. --Orrery.

   3. Not in accordance with good taste; as, a tasteless
      arrangement of drapery. -- {Taste"less*ly}, adv. --
      {Taste"less*ness}, n.

Source : WordNet®

tasteless
     adj 1: lacking flavor [ant: {tasteful}]
     2: lacking aesthetic or social taste [syn: {in poor taste(p)}]
        [ant: {tasteful}]
     3: not pleasing to the sense of taste [syn: {insipid}]
     4: deficient in tastefulness; "coarse and tasteless luxury"