Source : Webster's Revised Unabridged Dictionary (1913)

Iconoclast \I*con"o*clast\, n. [Gr. e'ikw`n image + ? to break:
   cf. F. iconoclaste.]
   1. A breaker or destroyer of images or idols; a determined
      enemy of idol worship.

   2. One who exposes or destroys impositions or shams; one who
      attacks cherished beliefs; a radical.

Source : WordNet®

iconoclast
     n : someone who tries to destroy traditional ideas or
         institutions [syn: {image breaker}]