Aix-la-Chapelle vs Aachen

Aix-la-Chapelle and Aachen both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aix-la-Chapelle	Yes	No	No	No
Aachen	Yes	No	No	No

As nouns, Aix-la-Chapelle and Aachen are synonyms defined as:

Aix-la-Chapelle and Aachen: a city in western Germany near the Dutch and Belgian borders; formerly it was Charlemagne's northern capital

Other synonyms of Aix-la-Chapelle include Aken.

Aix-la-Chapelle (noun)	Aachen (noun)
a city in western Germany near the Dutch and Belgian borders; formerly it was Charlemagne's northern capital	a city in western Germany near the Dutch and Belgian borders; formerly it was Charlemagne's northern capital