pignut vs hickory

pignut and hickory both are nouns.

Word	Noun	Adjective	Verb	Adverb
pignut	Yes	No	No	No
hickory	Yes	No	No	No

As nouns, hickory is a hypernym of pignut; that is, hickory is a word with a broader meaning than pignut:

Other hypernyms of pignut include hickory tree.

pignut (noun)	hickory (noun)
an American hickory tree having bitter nuts	American hardwood tree bearing edible nuts
	valuable tough heavy hardwood from various hickory trees