Ireland vs Hibernia

Ireland and Hibernia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ireland	Yes	No	No	No
Hibernia	Yes	No	No	No

As nouns, Ireland and Hibernia are synonyms defined as:

Ireland and Hibernia: an island comprising the republic of Ireland and Northern Ireland

Other synonyms of Ireland include Emerald Isle.

Ireland (noun)	Hibernia (noun)
an island comprising the republic of Ireland and Northern Ireland	an island comprising the republic of Ireland and Northern Ireland
a republic consisting of 26 of 32 counties comprising the island of Ireland; achieved independence from the United Kingdom in 1921