Muscat and Oman vs Sultanate of Oman

Muscat and Oman and Sultanate of Oman both are nouns.

Word	Noun	Adjective	Verb	Adverb
Muscat and Oman	Yes	No	No	No
Sultanate of Oman	Yes	No	No	No

As nouns, Muscat and Oman and Sultanate of Oman are synonyms defined as:

Muscat and Oman and Sultanate of Oman: a strategically located monarchy on the southern and eastern coasts of the Arabian Peninsula; the economy is dominated by oil

Other synonyms of Muscat and Oman include Oman.

Muscat and Oman (noun)	Sultanate of Oman (noun)
a strategically located monarchy on the southern and eastern coasts of the Arabian Peninsula; the economy is dominated by oil	a strategically located monarchy on the southern and eastern coasts of the Arabian Peninsula; the economy is dominated by oil