The Collaborative International Dictionary of English v.0.48:

Rietboc \Riet"boc\, n. [D. riet reed + bok buck.] (Zool.)
   The reedbuck, a South African antelope (Cervicapra
   arundinacea); -- so called from its frequenting dry places
   covered with high grass or reeds. Its color is yellowish
   brown. Called also inghalla, and rietbok.
   [1913 Webster]