Monitor vs USS Monitor

Monitor and USS Monitor both are nouns.

Word	Noun	Adjective	Verb	Adverb
Monitor	Yes	No	No	No
USS Monitor	Yes	No	No	No

As nouns, Monitor and USS Monitor are synonyms defined as:

Monitor and USS Monitor: an ironclad vessel built by Federal forces to do battle with the Merrimac

Monitor (noun)	USS Monitor (noun)
an ironclad vessel built by Federal forces to do battle with the Merrimac	an ironclad vessel built by Federal forces to do battle with the Merrimac