Gaul adjectives are listed in this post. Each word below can often be found in front of the noun gaul in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing GAUL.
ancient, central
cisalpine, eastern
gigantic, haughty
northern, old
southern
Hope this word list had the adjective used with gaul you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.
Please add more adjectives to make this list more complete: