coal-bed
UK[ˈkəʊl bɛd]US[ˈkoʊl bɛd]
n
A layer or stratum of coal within the earth.
Morpheme Breakdown
coal
bed
coal
fuel
bed
layer
Etymology
The compound "coal-bed" is a transparent combination of two native English words, each with deep Germanic roots. "Coal" originates from the Old English col, referring to burning embers or charcoal, a term with cognates across Germanic languages. "Bed" derives from Old English bedd, which originally meant a sleeping place but semantically broadened to denote any flat supporting layer or stratum, such as a garden bed or a riverbed. When combined in the late 18th century, primarily within geological and mining contexts, the term logically constructed the meaning of a natural stratum or layer composed of coal, directly reflecting the literal senses of its components.
Analysis
Structure: coal (fuel) + bed (layer)
coal: From Old English col, meaning "charcoal, live coal". Germanic origin, related to Dutch kool and German Kohle.
bed: From Old English bedd, meaning "a sleeping place, garden plot, layer". Germanic origin, related to Dutch bed and German Bett.
Examples
The miners accessed a rich coal-bed several hundred feet below the surface.
Geological surveys are used to map the extent and depth of a coal-bed.
Methane gas is often trapped within a coal-bed, posing a safety hazard.