hoarder vs niggard

hoarder and niggard both are nouns.

Word	Noun	Adjective	Verb	Adverb
hoarder	Yes	No	No	No
niggard	Yes	No	No	No

As nouns, niggard is a hyponym of hoarder; that is, niggard is a word with a more specific, narrower meaning than hoarder:

Other hyponyms of hoarder include magpie, pack rat, scavenger, miser, churl, scrooge, skinflint, penny pincher.

hoarder (noun)	niggard (noun)
a person who accumulates things and hides them away for future use	a selfish person who is unwilling to give or spend