bitternut vs bitter pignut

bitternut and bitter pignut both are nouns.

Word	Noun	Adjective	Verb	Adverb
bitternut	Yes	No	No	No
bitter pignut	Yes	No	No	No

As nouns, bitternut and bitter pignut are synonyms defined as:

bitternut and bitter pignut: hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts

Other synonyms of bitternut include bitter hickory, bitternut hickory, Carya cordiformis, swamp hickory.

bitternut (noun)	bitter pignut (noun)
hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts	hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts