Source : Webster's Revised Unabridged Dictionary (1913)

Bister \Bis"ter\, Bistre \Bis"tre\, n. [F. bistre a color made
   of soot; of unknown origin. Cf., however, LG. biester
   frowning, dark, ugly.] (Paint.)
   A dark brown pigment extracted from the soot of wood.

Source : WordNet®

bister
     n : a water-soluble brownish-yellow pigment made by boiling wood
         soot [syn: {bistre}]