St. Martin vs Saint Maarten

St. Martin and Saint Maarten both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Martin	Yes	No	No	No
Saint Maarten	Yes	No	No	No

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

St. Martin and Saint Maarten: an island in the western Leeward Islands; administered jointly by France and the Netherlands

Other synonyms of St. Martin include Saint Martin, Sint Maarten, St. Maarten.

St. Martin (noun)	Saint Maarten (noun)
an island in the western Leeward Islands; administered jointly by France and the Netherlands	an island in the western Leeward Islands; administered jointly by France and the Netherlands
French bishop who is a patron saint of France (died in 397)