VOORN, one of the islands of Holland, bounded by the river Maas, which divides it from the continent, and the island of IJemunde, on the north; by the sea called Bies bosch, on the east; by another branch of the Maas, which divides it from the islands of Gorce and Overlackee, on the south; and by the German sea on the west; being about 24 miles long, and five broad.