The Collaborative International Dictionary of English v.0.48:

Haiti \Haiti\ n.
   1. a country on the island of Hispaniola.
      [WordNet 1.5]

   2. an island in the West Indies.

   Syn: Hispaniola, Hayti.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Haiti
    n 1: a republic in the West Indies on the western part of the
         island of Hispaniola; achieved independence from France in
         1804; the poorest and most illiterate nation in the western
         hemisphere [syn: Haiti, Republic of Haiti]
    2: an island in the West Indies [syn: Hispaniola, Haiti,
       Hayti]