duramen vs heartwood

duramen and heartwood both are nouns.

Word	Noun	Adjective	Verb	Adverb
duramen	Yes	No	No	No
heartwood	Yes	No	No	No

As nouns, duramen and heartwood are synonyms defined as:

duramen and heartwood: the older inactive central wood of a tree or woody plant; usually darker and denser than the surrounding sapwood

duramen (noun)	heartwood (noun)
the older inactive central wood of a tree or woody plant; usually darker and denser than the surrounding sapwood	the older inactive central wood of a tree or woody plant; usually darker and denser than the surrounding sapwood