Source : Webster's Revised Unabridged Dictionary (1913)

Dreamer \Dream"er\, n.
   1. One who dreams.

   2. A visionary; one lost in wild imaginations or vain schemes
      of some anticipated good; as, a political dreamer.

Source : WordNet®

dreamer
     n 1: someone who is dreaming
     2: someone guided more by ideals than by practical
        considerations [syn: {idealist}]
     3: a person who escapes into a world of fantasy [syn: {escapist},
         {wishful thinker}]