Saint Kitts vs St. Kitts

Saint Kitts and St. Kitts both are nouns.

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

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

Saint Kitts and St. Kitts: the largest of the islands comprising Saint Christopher-Nevis

Other synonyms of Saint Kitts include Saint Christopher, St. Christopher.

Saint Kitts (noun)	St. Kitts (noun)
the largest of the islands comprising Saint Christopher-Nevis	the largest of the islands comprising Saint Christopher-Nevis