The Collaborative International Dictionary of English v.0.48:

Genipap \Gen"i*pap\, n. (Bot.)
   The edible fruit of a West Indian tree (Genipa Americana)
   of the order Rubiace[ae]. It is oval in shape, as a large
   as a small orange, of a pale greenish color, and with dark
   purple juice.
   [1913 Webster]

WordNet (r) 3.0 (2006):

genipap
    n 1: a succulent orange-sized tropical fruit with a thick rind
         [syn: genipap, genipap fruit]