Gaul (Latin: Gallia) was the name given in ancient times to the area of Western Europe that included northern Italy, France, Belgium, western Switzerland and the parts of the Netherlands and Germany on the west bank of the Rhine river. Many Celtic tribes lived in the region and were known by the Romans simply as "Gauls".
In English, the word Gaul (French: Gaulois) may mean a Celtic inhabitant of that region or it may mean all ancient speakers of the Gaulish language. In this way, "Gaul" and "Celt" are sometimes used in the same sense.
In Greek, modern-day France is called Γαλλία (same as the Latin Gallia) and the term for a Gaulish person is Γαλατία (Galatia).