The Collaborative International Dictionary of English v.0.48:

macamba \macamba\ n.
   A tropical American feather palm (Acrocomia aculeata)
   having a swollen spiny trunk and edible nuts.

   Syn: grugru, gri gri, grugru palm, Acrocomia aculeata.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

macamba
    n 1: tropical American feather palm having a swollen spiny trunk
         and edible nuts [syn: grugru, gri-gri, grugru palm,
         macamba, Acrocomia aculeata]