penny pincher vs hoarder

penny pincher and hoarder both are nouns.

Word	Noun	Adjective	Verb	Adverb
penny pincher	Yes	No	No	No
hoarder	Yes	No	No	No

As nouns, hoarder is a hypernym of penny pincher; that is, hoarder is a word with a broader meaning than penny pincher:

penny pincher: someone who is excessively careful with money (who pinches every penny before letting go of it)
hoarder: a person who accumulates things and hides them away for future use

penny pincher (noun)	hoarder (noun)
someone who is excessively careful with money (who pinches every penny before letting go of it)	a person who accumulates things and hides them away for future use