Noun
coal suitable for use under steam boilers
Source: WordNetGlamorgan steam coal quickly became a sought-after commodity for navies all over the world and its production increased to meet the demand. Source: Internet
This population growth, a result of the growth of the steam coal trade (see below) was increasingly concentrated in the previously agricultural areas of Blaengwawr and Cefnpennar to the south of the town. Source: Internet