n. The soil underneath the surface / topsoil and above the bedrock
the GNU version of the Collaborative International Dictionary of English
n. The soil beneath the surface; understratum; subsoil.
The Century Dictionary and Cyclopedia
n. Soil beneath the surface; subsoil.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the layer of soil between the topsoil and bedrock
Word Usage
"We have rich lands, a richer undersoil, unharnessed power in our rivers, falls and forests; our lakes and rivers are also rich in natural resources of all kind."