pignut vs brown hickory

pignut and brown hickory both are nouns.

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

As nouns, pignut and brown hickory are synonyms defined as:

Other synonyms of pignut include black hickory, Carya glabra, pignut hickory.

pignut (noun)	brown hickory (noun)
an American hickory tree having bitter nuts	an American hickory tree having bitter nuts