The Collaborative International Dictionary of English v.0.48:

Curacao \Cu`ra*[,c]ao"\, Curacoa \Cu`ra*[,c]oa"\, (k??`r?-s?"),
   n.
   A liqueur, or cordial, flavored with the peel from the sour
   orange, and sometimes with cinnamon and mace; -- first made
   at the island of Cura[,c]cao in the Netherlands Antilles near
   Venezuela.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

curacoa
    n 1: flavored with sour orange peel [syn: curacao, curacoa]