lignite

A soft, brownish-black coal in which the alteration of vegetable matter has proceeded further than in peat but not as far as in bituminous coal.

Brown-coal; imperfectly formed coal, or that in which the original form of the wood is so distinctly preserved that it can be easily recognized by the unaided eye.

Mineral coal retaining the texture of the wood from which it was formed, and burning with an empyreumatic odor. It is of more recent origin than the anthracite and bituminous coal of the proper coal series. Called also brown coal, wood coal.

A low-grade, brownish-black coal

intermediate between peat and bituminous coal