Kingdom of Saudi Arabia vs Gulf States

Kingdom of Saudi Arabia and Gulf States both are nouns.

Word	Noun	Adjective	Verb	Adverb
Kingdom of Saudi Arabia	Yes	No	No	No
Gulf States	Yes	No	No	No

Kingdom of Saudi Arabia (noun)	Gulf States (noun)
an absolute monarchy occupying most of the Arabian Peninsula in southwest Asia; vast oil reserves dominate the economy	a region of the United States comprising states bordering the Gulf of Mexico; Alabama and Florida and Louisiana and Mississippi and Texas
	the countries in southwestern Asia that border the Persian Gulf