gall, Gaul

Gall or gall means bile, or some other bitter substance--
"A honey tongue, a heart of gall..."
"...they gave him wine to drink, mixed with gall..."

Gall also means to cause a sore by rubbing--
Fasten the saddle properly, or it will gall the horse.

Gall may mean a growth on a tree or plant--
A gall like this may be caused by insects.

Gall may also mean a brazen, rude, impudent, attitude--
He had the gall to tell me I ought to retire!

Gall may also mean to cause resentment or bitterness--
Being slighted may gall him, but he'll get over it.

Gaul ( always capitalized, rhymes with gall ) means an ancient country located where France is today, but a bit larger, including parts of the territory of Belgium, Germany, and Italy--
"All Gaul is divided into three parts."
The buildings the Romans left behind in Gaul are still a tourist attraction in France today.

Gaul may also mean one of the people of the ancient country that is France today--
Vercingetorix, the famous Gaul, was captured by the Romans.

Now that you know that, you can say--
"He had the gall to tell me that he knows more about Gaul than anyone."

Note--"Gallic" ( always capitalized ) describes someone or something from Gaul--
Julius Caesar wrote an account of the Gallic wars that is still a classic.