St. Martin vs Saint Martin

St. Martin and Saint Martin both are nouns.

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

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

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

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

St. Martin (noun)	Saint Martin (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)