white walnut vs butternut tree

white walnut and butternut tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
white walnut	Yes	No	No	No
butternut tree	Yes	No	No	No

As nouns, white walnut and butternut tree are synonyms defined as:

white walnut and butternut tree: North American walnut tree having light-brown wood and edible nuts; source of a light-brown dye

Other synonyms of white walnut include butternut, Juglans cinerea.

white walnut (noun)	butternut tree (noun)
North American walnut tree having light-brown wood and edible nuts; source of a light-brown dye	North American walnut tree having light-brown wood and edible nuts; source of a light-brown dye