👉 The term "subterraneal" is defined as a region or space that lies beneath the surface of the earth, often referred to as an underwater area. Subterranean refers to the underground part of the earth's surface and encompasses all the layers below the surface, including the lithosphere (the solid outer layer), the mantle (which is made up of iron and nickel), and the crust (which includes the upper layers of the Earth). This term is used in geology and engineering contexts
