magma
[U] Uncountable
pl: magmas
This term describes a high-temperature fluid state of rock that exists under immense pressure. It is distinguished from lava by its location; once the substance breaks the surface and becomes exposed to the atmosphere, it is renamed. This transition marks a shift from a subterranean geological force to an active surface phenomenon. In a descriptive sense, the word evokes images of intense heat, glowing reds and oranges, and a slow, viscous flow. It carries a connotation of latent power and imminent danger, often used in scientific contexts to explain the mechanics of tectonic plates and volcanic activity.
Used exclusively as a mass noun to describe the molten material, such as saying there is a large volume of magma beneath the crust.