a stratum of coal separated by a non-carbonaceous layer from overlying coal.

An open cast mine consisting of near horizontal passages dug into the surface; a mine consisting of one or more near horizontal shafts or passages…

an important seam, which in the southern part of the Shropshire coalfield is the topmost.

a very thick seam of coal near Dudley.

Mining. A thin seam of coal or deposit of ore overlying a principal seam or vein. Frequently attributive, as rider seam, rider vein.

measuring, or having, ten feet; figurative phr. ten feet tall used contextually to convey extreme self-assurance or pride; ten-foot coal, a thick…

see quot. 1855, and cf. top coal n.

a seam of coal a yard thick.

= yard-coal n.

(see quot. 1867).

Coal Mining. A main seam of coal; (also, by extension) a coal mine situated on it. Cf. main coal n. at main, adj.2 compounds 2.

Mining. A coal bed or ore deposit worked above the water table by surface excavations or drifts. Obsolete. rare.

English regional (Staffordshire). Coal Mining. A steeply inclined seam of coal; an edge seam. Usually attributive.

see quot.; hence thick-coalman.

a seam of ‘thick coal’; also attributive.

(also attributive), see quots.