Source : Webster's Revised Unabridged Dictionary (1913)

Centerpiece \Cen"ter*piece`\, Centrepiece \Cen"tre*piece`\, n.
   An ornament to be placed in the center, as of a table,
   ceiling, atc.; a central article or figure.

Source : WordNet®

centerpiece
     n 1: the central or most important feature; "education was the
          centerpiece of the Democratic Party's political
          platform" [syn: {centrepiece}]
     2: something placed at the center of something else (as on a
        table) [syn: {centrepiece}]