A hard incendiary substance that burns slowly and is difficult to extinguish, consisting chiefly of a mixture of resin, sulphur, and potassium nitrate.
Origin
Mid 19th century.
Definition of rock-fire in US English:
rock-fire
noun
historical
A hard incendiary substance that burns slowly and is difficult to extinguish, consisting chiefly of a mixture of resin, sulphur, and potassium nitrate.