Cyprus vs Republic of Cyprus

Cyprus and Republic of Cyprus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cyprus	Yes	No	No	No
Republic of Cyprus	Yes	No	No	No

As nouns, Cyprus and Republic of Cyprus are synonyms defined as:

Cyprus and Republic of Cyprus: a country on the island of Cyprus; 80% of the people are of Greek origin and 20% or Turkish origin

Cyprus (noun)	Republic of Cyprus (noun)
a country on the island of Cyprus; 80% of the people are of Greek origin and 20% or Turkish origin	a country on the island of Cyprus; 80% of the people are of Greek origin and 20% or Turkish origin
an island in the eastern Mediterranean