New York vs Ground Zero

New York and Ground Zero both are nouns.

Word	Noun	Adjective	Verb	Adverb
New York	Yes	No	No	No
Ground Zero	Yes	No	No	No

New York (noun)	Ground Zero (noun)
a Mid-Atlantic state; one of the original 13 colonies, with capital Albany	the site of the World Trade Center before it was destroyed
the largest city in New York State and in the United States; located in southeastern New York at the mouth of the Hudson river; a major financial and cultural center
one of the British colonies that formed the United States, with capital New York City