The Collaborative International Dictionary of English v.0.48:

Caperberry \Ca"per*ber`ry\, n.
   1. The small olive-shaped berry of the European and Oriental
      caper, said to be used in pickles and as a condiment.
      [1913 Webster]

   2. The currantlike fruit of the African and Arabian caper
      (Capparis sodado).
      [1913 Webster] Caper bush