IJssel river vs IJssel

IJssel river and IJssel both are nouns.

Word	Noun	Adjective	Verb	Adverb
IJssel river	Yes	No	No	No
IJssel	Yes	No	No	No

As nouns, IJssel river and IJssel are synonyms defined as:

IJssel river and IJssel: a river in the central Netherlands flowing north to the IJsselmeer

IJssel river (noun)	IJssel (noun)
a river in the central Netherlands flowing north to the IJsselmeer	a river in the central Netherlands flowing north to the IJsselmeer