United States Navy vs Navy

United States Navy and Navy both are nouns.

Word	Noun	Adjective	Verb	Adverb
United States Navy	Yes	No	No	No
Navy	Yes	No	No	No

As nouns, United States Navy and Navy are synonyms defined as:

United States Navy and Navy: the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces

Other synonyms of United States Navy include US Navy, USN.

United States Navy (noun)	Navy (noun)
the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces	the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces