USS Monitor vs Monitor

USS Monitor and Monitor both are nouns.

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

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

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

USS Monitor (noun)	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