duramen

English Thesaurus

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

hypernym	:	wood,
definition	:	the hard fibrous lignified substance under the bark of trees (noun.substance)

substance meronym	:	tree,
definition	:	a tall perennial woody plant having a main trunk and branches forming a distinct elevated crown; includes both gymnosperms and angiosperms (noun.plant)