five dollar bill vs five-spot

five dollar bill and five-spot both are nouns.

Word	Noun	Adjective	Verb	Adverb
five dollar bill	Yes	No	No	No
five-spot	Yes	No	No	No

As nouns, five dollar bill and five-spot are synonyms defined as:

Other synonyms of five dollar bill include fiver.

five dollar bill (noun)	five-spot (noun)
a United States bill worth 5 dollars	a playing card or a domino or a die whose upward face shows five pips
	California annual having white flowers with a deep purple blotch on each petal
	a United States bill worth 5 dollars