Source : Webster's Revised Unabridged Dictionary (1913)

Insufferable \In*suf"fer*a*ble\, a.
   1. Incapable of being suffered, borne, or endured;
      insupportable; unendurable; intolerable; as, insufferable
      heat, cold, or pain; insufferable wrongs. --Locke.

   2. Offensive beyond endurance; detestable.

            A multitude of scribblers who daily pester the world
            with their insufferable stuff.        --Dryden.

Source : WordNet®

insufferable
     adj : used of persons or their behavior; "impossible behavior";
           "insufferable insolence" [syn: {impossible}, {unacceptable},
            {unsufferable}]