natural gas extracted from an underground coal formation

(inorganic chemistry) Any of the soft, light, reactive metals of Group 1 of the periodic table; lithium, sodium, potassium, rubidium, cesium, and francium.

Metal worked into a thin, flat sheet, used widely as construction material and raw material for a multitude of industrial products. It is thicker than foil and thinner than plate.

(philosophy) A philosopher who specializes in the scholarly study of metaphysics.

(chemistry) Any metal at the lower end of the electrochemical series that oxidizes readily. / (metallurgy) The metal to be welded (rather than that used to weld). / A common or inexpensive metal.

(music) A subgenre of heavy metal music from the 1990s and 2000s with some sounds and influences from grunge and hip-hop.

(music) A subgenre of heavy metal characterised by a slow tempo and low-tuned guitars, often emphasizing despairing lyrics.

Iron, or similar metals worked by a blacksmith

In a meteoric manner.

(dated) A person who works in metal (the type of material). / A person skilled in metallurgy.