CO vs Colorado River

CO and Colorado River both are nouns.

Word	Noun	Adjective	Verb	Adverb
CO	Yes	No	No	No
Colorado River	Yes	No	No	No

CO (noun)	Colorado River (noun)
a state in west central United States in the Rocky Mountains	an important river in the southwestern United States; rises in the Rocky Mountains of northern Colorado and flows southwest through Utah into Arizona (where it flows through the Grand Canyon) and then southward through the southern tip of Nevada, then forming the border between California and Arizona and finally into Mexico where it empties into the Gulf of California; the main source of water in the southwestern United States
one who refuses to serve in the armed forces on grounds of conscience	a river in Texas; flows southeast into the Gulf of Mexico
an odorless very poisonous gas that is a product of incomplete combustion of carbon