understratum

As nouns the difference between terms and understratum

is that terms is while understratum is the layer, or stratum, of earth on which the soil rests; the subsoil.

As nouns the difference between subsoil and understratum

is that subsoil is the layer of earth that is below the topsoil while understratum is the layer, or stratum, of earth on which the soil rests; the subsoil.

As nouns the difference between soil and understratum

is that soil is a mixture of sand and organic material, used to support plant growth while understratum is the layer, or stratum, of earth on which the soil rests; the subsoil.

As a verb soil

is to make dirty.

As a proper noun earth

is the third planet in order from the sun, upon which humans live represented in astronomy and astrology by.

As a noun understratum is

the layer, or stratum, of earth on which the soil rests; the subsoil.

As nouns the difference between stratum and understratum

is that stratum is one of several parallel horizontal layers of material arranged one on top of another while understratum is the layer, or stratum, of earth on which the soil rests; the subsoil.

As nouns the difference between layer and understratum

is that layer is a single thickness of some material covering a surface while understratum is the layer, or stratum, of earth on which the soil rests; the subsoil.

As a verb layer

is (ambitransitive) to cut or divide (something) into layers.