Somme River vs Battle of the Somme

Somme River and Battle of the Somme both are nouns.

Word	Noun	Adjective	Verb	Adverb
Somme River	Yes	No	No	No
Battle of the Somme	Yes	No	No	No

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

Other synonyms of Somme River include Somme.

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

Other synonyms of Somme River include Somme.

Somme River (noun)	Battle of the Somme (noun)
battle in World War I (1916)	battle in World War I (1916)
battle of World War II (1944)	battle of World War II (1944)