charcoal
/ˈtʃɑ:kəul; `tʃɑrˌkol/ n
1 [U] black substance made by burning wood slowly in an oven with a little air, used as a filtering material or as fuel or for drawing 木炭
a stick/piece/lump of charcoal 一根、 一块木炭
[attrib 作定语]
a charcoal sketch 炭笔素描.
2 (also charcoal `grey) [U]
very dark grey colour 深灰色.