duramen Meaning, Definition & Usage

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

WordNet

Du*ra"men noun
Etymology
L., hardness, a hardened, i. e., ligneous, vine branch, fr. durare to harden. See Dure.
Definitions
  1. (Bot.) The heartwood of an exogenous tree.

Webster 1913