The Collaborative International Dictionary of English v.0.48:

dreamy \dream"y\ (dr[=e]m"[y^]), a. [Compar. Dreamier
   (dr[=e]m"[i^]*[~e]r); superl. Dreamiest.]
   1. Abounding in dreams or given to dreaming; appropriate to,
      or like, dreams; visionary. "The dreamy dells."
      --Tennyson.
      [1913 Webster]

   2. soothing; restful; as, dreamy music.
      [PJC]

   3. Like what one dreams of; wonderful; delightful; marvelous;
      ideal; as, a dreamy house and garden. [informal]
      [PJC]

   4. Prone to indulge in fantasy or daydreaming; as, a dreamy
      young girl.
      [PJC]