Republic of Slovenia vs Slovenia

Republic of Slovenia and Slovenia both are nouns.

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

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

Republic of Slovenia and Slovenia: a mountainous republic in central Europe; formerly part of the Habsburg monarchy and Yugoslavia; achieved independence in 1991

Other synonyms of Republic of Slovenia include Slovenija.

Republic of Slovenia (noun)	Slovenia (noun)
a mountainous republic in central Europe; formerly part of the Habsburg monarchy and Yugoslavia; achieved independence in 1991	a mountainous republic in central Europe; formerly part of the Habsburg monarchy and Yugoslavia; achieved independence in 1991