Bluegrass State vs Kentucky

Bluegrass State and Kentucky both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bluegrass State	Yes	No	No	No
Kentucky	Yes	No	No	No

As nouns, Bluegrass State and Kentucky are synonyms defined as:

Bluegrass State and Kentucky: a state in east central United States; a border state during the American Civil War; famous for breeding race horses

Other synonyms of Bluegrass State include Ken., KY.

Bluegrass State (noun)	Kentucky (noun)
a state in east central United States; a border state during the American Civil War; famous for breeding race horses	a state in east central United States; a border state during the American Civil War; famous for breeding race horses