humin Meaning, Definition & Usage

  1. noun a black humic substance that is not soluble in water

WordNet

Hu"min noun
Etymology
L. humus the earth, ground.
Definitions
  1. (Chem.) A bitter, brownish yellow, amorphous substance, extracted from vegetable mold, and also produced by the action of acids on certain sugars and carbohydrates; -- called also humic acid, ulmin, gein, ulmic or geic acid, etc.

Webster 1913