The Collaborative International Dictionary of English v.0.48:

Lignite \Lig"nite\ (l[i^]g"n[imac]t), n. [L. lignum wood: cf. F.
   lignite.] (Min.)
   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.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Brown \Brown\ (broun), a. [Compar. Browner; superl.
   Brownest.] [OE. brun, broun, AS. br?n; akin to D. bruin,
   OHG. br?n, Icel. br?nn, Sw. brun, Dan. bruun, G. braun, Lith.
   brunas, Skr. babhru. [root]93, 253. Cf. Bruin, Beaver,
   Burnish, Brunette.]
   Of a dark color, of various shades between black and red or
   yellow.
   [1913 Webster]

         Cheeks brown as the oak leaves.          --Longfellow.
   [1913 Webster]

   Brown Bess, the old regulation flintlock smoothbore musket,
      with bronzed barrel, formerly used in the British army.

   Brown bread
   (a) Dark colored bread; esp. a kind made of unbolted wheat
       flour, sometimes called in the United States Graham
       bread. "He would mouth with a beggar though she smelt
       brown bread and garlic." --Shak.
   (b) Dark colored bread made of rye meal and Indian meal, or
       of wheat and rye or Indian; rye and Indian bread. [U.S.]


   Brown coal, wood coal. See Lignite.

   Brown hematite or Brown iron ore (Min.), the hydrous iron
      oxide, limonite, which has a brown streak. See Limonite.


   Brown holland. See under Holland.

   Brown paper, dark colored paper, esp. coarse wrapping
      paper, made of unbleached materials.

   Brown spar (Min.), a ferruginous variety of dolomite, in
      part identical with ankerite.

   Brown stone. See Brownstone.

   Brown stout, a strong kind of porter or malt liquor.

   Brown study, a state of mental abstraction or serious
      reverie. --W. Irving.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coal \Coal\ (k[=o]l), n. [AS. col; akin to D. kool, OHG. chol,
   cholo, G. kohle, Icel. kol, pl., Sw. kol, Dan. kul; cf. Skr.
   jval to burn. Cf. Kiln, Collier.]
   1. A thoroughly charred, and extinguished or still ignited,
      fragment from wood or other combustible substance;
      charcoal.
      [1913 Webster]

   2. (Min.) A black, or brownish black, solid, combustible
      substance, dug from beds or veins in the earth to be used
      for fuel, and consisting, like charcoal, mainly of carbon,
      but more compact, and often affording, when heated, a
      large amount of volatile matter.
      [1913 Webster]

   Note: This word is often used adjectively, or as the first
         part of self-explaining compounds; as, coal-black; coal
         formation; coal scuttle; coal ship. etc.
         [1913 Webster]

   Note: In England the plural coals is used, for the broken
         mineral coal burned in grates, etc.; as, to put coals
         on the fire. In the United States the singular in a
         collective sense is the customary usage; as, a hod of
         coal.
         [1913 Webster]

   Age of coal plants. See Age of Acrogens, under Acrogen.


   Anthracite or Glance coal. See Anthracite.

   Bituminous coal. See under Bituminous.

   Blind coal. See under Blind.

   Brown coal or Brown Lignite. See Lignite.

   Caking coal, a bituminous coal, which softens and becomes
      pasty or semi-viscid when heated. On increasing the heat,
      the volatile products are driven off, and a coherent,
      grayish black, cellular mass of coke is left.

   Cannel coal, a very compact bituminous coal, of fine
      texture and dull luster. See Cannel coal.

   Coal bed (Geol.), a layer or stratum of mineral coal.

   Coal breaker, a structure including machines and machinery
      adapted for crushing, cleansing, and assorting coal.

   Coal field (Geol.), a region in which deposits of coal
      occur. Such regions have often a basinlike structure, and
      are hence called coal basins. See Basin.

   Coal gas, a variety of carbureted hydrogen, procured from
      bituminous coal, used in lighting streets, houses, etc.,
      and for cooking and heating.

   Coal heaver, a man employed in carrying coal, and esp. in
      putting it in, and discharging it from, ships.

   Coal measures. (Geol.)
      (a) Strata of coal with the attendant rocks.
      (b) A subdivision of the carboniferous formation, between
          the millstone grit below and the Permian formation
          above, and including nearly all the workable coal beds
          of the world.

   Coal oil, a general name for mineral oils; petroleum.

   Coal plant (Geol.), one of the remains or impressions of
      plants found in the strata of the coal formation.

   Coal tar. See in the Vocabulary.

   To haul over the coals, to call to account; to scold or
      censure. [Colloq.]

   Wood coal. See Lignite.
      [1913 Webster]

WordNet (r) 3.0 (2006):

brown coal
    n 1: intermediate between peat and bituminous coal [syn:
         lignite, brown coal, wood coal]