an ancient region in W Europe, including the modern areas of N Italy, France, Belgium, and the S Netherlands: consisted of two main divisions, one part S of the Alps (Cisalpine Gaul) and another part N of the Alps (Transalpine Gaul).
2.
Latin, Gallia.a province of the ancient Roman Empire, including the territory corresponding to modern France, Belgium, the S Netherlands, Switzerland, N Italy, and Germany W of the Rhine.