coal ball
noun
a spherical mass of mineral and plant material embedded in coal beds, ranging in size from that of a pea to that of a boulder.
Origin of coal ball
First recorded in 1735–45
Words nearby coal ball
coagulopathy,
coagulum,
coahuila,
coak,
coal,
coal ball,
coal car,
coal cutter,
coal field,
coal gas,
coal heaver