Gallia vs Gaul

Gallia and Gaul both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gallia	Yes	No	No	No
Gaul	Yes	No	No	No

As nouns, Gallia and Gaul are synonyms defined as:

Gallia and Gaul: an ancient region of western Europe that included what is now northern Italy and France and Belgium and part of Germany and the Netherlands

Gallia (noun)	Gaul (noun)
an ancient region of western Europe that included what is now northern Italy and France and Belgium and part of Germany and the Netherlands	an ancient region of western Europe that included what is now northern Italy and France and Belgium and part of Germany and the Netherlands
	a Celt of ancient Gaul
	a person of French descent