Ilium vs Troy

Ilium and Troy both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ilium	Yes	No	No	No
Troy	Yes	No	No	No

As nouns, Ilium and Troy are synonyms defined as:

Ilium and Troy: an ancient city in Asia Minor that was the site of the Trojan War

Other synonyms of Ilium include Ilion.

Ilium (noun)	Troy (noun)
an ancient city in Asia Minor that was the site of the Trojan War	an ancient city in Asia Minor that was the site of the Trojan War