Ground Zero vs New York

Ground Zero and New York both are nouns.

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

Ground Zero (noun)	New York (noun)
the site of the World Trade Center before it was destroyed	a Mid-Atlantic state; one of the original 13 colonies, with capital Albany
	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