noun

• (countable, uncountable) impure carbon obtained by destructive distillation of wood or other organic matter, that is, heating it in the absence of oxygen.
  "The grate was laid with charcoal, to that she put a light, and then, as if she had forgotten something, hurried to the library, and carefully locked the door. First returning to see that the fire had kindled, she then went to the window, which, with the first gleam of moonlight, she cautiously unclosed, and stepped into the shrubbery."
• (countable) A stick of black carbon material used for drawing.
  "He takes the prepared charcoal used by artists, brings it to a white heat, and suddenly plunges it in a bath of mercury, of which the globules instantly penetrate the pores of charcoal, and may be said to metallize it."
• (countable) A drawing made with charcoal.