A natural dark brown to black graphitelike material used as a fuel, formed from fossilized plants and consisting of amorphous carbon with various organic and some inorganic compounds.
파생어
coaly [형]
예문
1. soft coal (역청탄) 2. small coal (분탄) 3. hard coal (무연탄) 4. brown coal (갈탄) 5. a good stove coal (난로용으로 적당한 석탄)
