Source : Webster's Revised Unabridged Dictionary (1913)

Boredom \Bore"dom\, n.
   1. The state of being bored, or pestered; a state of ennui.
      --Dickens.

   2. The realm of bores; bores, collectively.

Source : WordNet®

boredom
     n : the feeling of being bored by something tedious [syn: {ennui},
          {tedium}]