POLACCA, the Italian name for a three-masted merchant vessel, formerly common in the eastern waters of the Mediterranean. The masts were of one piece and the sails were square or lateen-shaped. The name appears in various forms in other languages, e.g. Fr. polaque or polacre, Sp. polacra, Du. polaak or Ger. Polack, and certainly means Polish, although there is no explanation to be found for any connexion between Poland and such a Mediterranean vessel.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)