Frankfurt on the Main vs Frankfurt

Frankfurt on the Main and Frankfurt both are nouns.

Word	Noun	Adjective	Verb	Adverb
Frankfurt on the Main	Yes	No	No	No
Frankfurt	Yes	No	No	No

As nouns, Frankfurt on the Main and Frankfurt are synonyms defined as:

Frankfurt on the Main and Frankfurt: a German city; an industrial and commercial and financial center

Other synonyms of Frankfurt on the Main include Frankfort.

Frankfurt on the Main (noun)	Frankfurt (noun)
a German city; an industrial and commercial and financial center	a German city; an industrial and commercial and financial center