The Collaborative International Dictionary of English v.0.48:

Grammatophyllum \Grammatophyllum\ n.
   A small genus of large epiphytic or terrestrial orchids of
   Southeastern Asia to Polynesia; the giants of the
   Orchidaceae having long narrow leaves and drooping flower
   clusters often 6 feet long.

   Syn: genus Grammatophyllum.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Grammatophyllum
    n 1: small genus of large epiphytic or terrestrial orchids of
         southeastern Asia to Polynesia; the giants of the
         Orchidaceae having long narrow leaves and drooping flower
         clusters often 6 feet long [syn: Grammatophyllum, genus
         Grammatophyllum]