The Collaborative International Dictionary of English v.0.48:

coconut \co"co*nut\, Cocoanut
\Co"coa*nut`\(k[=o]"k[-o]*n[u^]t`), n.
   1. the edible white meat of a coconut[3]; often shredded for
      use in e.g. cakes and curries.

   Syn: coconut meat.
        [WordNet 1.5]

   2. the cocoa palm.

   Syn: coconut palm, coco palm, coco, cocoa palm, coconut tree,
        Cocos nucifera.
        [WordNet 1.5]

   3. The large, hard-shelled oval nut of the cocoa palm. It has
      a fibrous husk containing a thick white fibrous meat much
      used as food, in confections, and in making oil. It has a
      central cavity filled (when fresh) with an agreeable milky
      liquid.
      [1913 Webster + WordNet 1.5] Cocobolo

WordNet (r) 3.0 (2006):

cocoanut
    n 1: large hard-shelled oval nut with a fibrous husk containing
         thick white meat surrounding a central cavity filled (when
         fresh) with fluid or milk [syn: coconut, cocoanut]