Monroe vs Marilyn Monroe

Monroe and Marilyn Monroe both are nouns.

Word	Noun	Adjective	Verb	Adverb
Monroe	Yes	No	No	No
Marilyn Monroe	Yes	No	No	No

As nouns, Monroe and Marilyn Monroe are synonyms defined as:

Monroe and Marilyn Monroe: United States film actress noted for sex appeal (1926-1962)

Other synonyms of Monroe include Norma Jean Baker.

Monroe (noun)	Marilyn Monroe (noun)
a town in north central Louisiana	United States film actress noted for sex appeal (1926-1962)
a town of southeast Michigan on Lake Erie
5th President of the United States; author of the Monroe Doctrine (1758-1831)
United States film actress noted for sex appeal (1926-1962)