banker's bill vs greenback

banker's bill and greenback both are nouns.

Word	Noun	Adjective	Verb	Adverb
banker's bill	Yes	No	No	No
greenback	Yes	No	No	No

As nouns, banker's bill and greenback are synonyms defined as:

banker's bill and greenback: a piece of paper money (especially one issued by a central bank)

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

banker's bill (noun)	greenback (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)