Second Battle of the Marne vs Marne River

Second Battle of the Marne and Marne River both are nouns.

Word	Noun	Adjective	Verb	Adverb
Second Battle of the Marne	Yes	No	No	No
Marne River	Yes	No	No	No

As nouns, Second Battle of the Marne and Marne River are synonyms defined as:

Second Battle of the Marne and Marne River: a World War I battle in northwestern France where the Allies defeated the Germans in 1918

Other synonyms of Second Battle of the Marne include Battle of the Marne, Belleau Wood, Chateau-Thierry.

Second Battle of the Marne (noun)	Marne River (noun)
a World War I battle in northwestern France where the Allies defeated the Germans in 1918	a World War I battle in northwestern France where the Allies defeated the Germans in 1918