king nut vs big shellbark hickory

king nut and big shellbark hickory both are nouns.

Word	Noun	Adjective	Verb	Adverb
king nut	Yes	No	No	No
big shellbark hickory	Yes	No	No	No

As nouns, king nut and big shellbark hickory are synonyms defined as:

king nut and big shellbark hickory: hickory of the eastern United States resembling the shagbark but having a much larger nut

Other synonyms of king nut include big shagbark, big shellbark, Carya laciniosa, king nut hickory.

king nut (noun)	big shellbark hickory (noun)
hickory of the eastern United States resembling the shagbark but having a much larger nut	hickory of the eastern United States resembling the shagbark but having a much larger nut