Source : Webster's Revised Unabridged Dictionary (1913)

Foolhardiness \Fool"har`di*ness\, n.
   Courage without sense or judgment; foolish rashness;
   recklessness. --Dryden.

Source : WordNet®

foolhardiness
     n : the trait of giving little thought to danger [syn: {recklessness},
          {rashness}]