Source : Webster's Revised Unabridged Dictionary (1913)

Havoc \Hav"oc\, v. t.
   To devastate; to destroy; to lay waste.

         To waste and havoc yonder world.         --Milton.

Havoc \Hav"oc\, interj. [See {Havoc}, n.]
   A cry in war as the signal for indiscriminate slaughter.
   --Toone.

         Do not cry havoc, where you should but hunt With modest
         warrant.                                 --Shak.

         Cry 'havoc,' and let slip the dogs of war! --Shak.

Havoc \Hav"oc\, n. [W. hafog devastation, havoc; or, if this be
   itself fr. E. havoc, cf. OE. havot, or AS. hafoc hawk, which
   is a cruel or rapacious bird, or F. hai, voux! a cry to
   hounds.]
   Wide and general destruction; devastation; waste.

         As for Saul, he made havoc of the church. --Acts viii.
                                                  3.

         Ye gods, what havoc does ambition make Among your
         works!                                   --Addison.

Source : WordNet®

havoc
     n : violent and needless disturbance [syn: {mayhem}]