bank note vs banknote

bank note and banknote both are nouns.

Word	Noun	Adjective	Verb	Adverb
bank note	Yes	No	No	No
banknote	Yes	No	No	No

As nouns, bank note and banknote are synonyms defined as:

bank note and banknote: a piece of paper money (especially one issued by a central bank)

Other synonyms of bank note include bank bill, banker's bill, bill, Federal Reserve note, government note, greenback, note.

bank note (noun)	banknote (noun)
a piece of paper money (especially one issued by a central bank)	a piece of paper money (especially one issued by a central bank)