St. Eustatius vs Saint Eustatius

St. Eustatius and Saint Eustatius both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Eustatius	Yes	No	No	No
Saint Eustatius	Yes	No	No	No

As nouns, St. Eustatius and Saint Eustatius are synonyms defined as:

St. Eustatius and Saint Eustatius: an island in the Netherlands Antilles

Other synonyms of St. Eustatius include Sint Eustatius.

St. Eustatius (noun)	Saint Eustatius (noun)
an island in the Netherlands Antilles	an island in the Netherlands Antilles