heartwood Meaning, Definition & Usage
-
noun the older inactive central wood of a tree or woody plant; usually darker and denser than the surrounding sapwood
duramen.
WordNet
Heart"wood` noun
Definitions
The hard, central part of the trunk of a tree, consisting of the old and matured wood, and usually differing in color from the outer layers. It is technically known as duramen, and distinguished from the softer sapwood or alburnum.