Sentence:  But through the oligopoly, <WSD>charcoal</WSD> fuel proliferated throughout London's trades and industries.  By the 1200s, brewers and bakers, tilemakers, glassblowers, pottery producers, and a range of other craftsmen all became hour-to-hour consumers of charcoal. 
Meaning of the word marked with <WSD> tags:  Made of charcoal.