the GNU version of the Collaborative International Dictionary of English
n. The bed, or stratum, of earth which lies immediately beneath the surface soil.
v. To turn up the subsoil of.
The Century Dictionary and Cyclopedia
n. The under-soil: the bed or stratum of earth or earthy matter which lies immediately under the surface soil, and which is less finely disintegrated and contains less organic matter than that.
In agriculture, to employ the subsoil-plow upon; plow up so as to cut into the subsoil.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the layer of soil between the topsoil and bedrock
Word Usage
"The B horizon, commonly referred to as subsoil, accumulates material washed out of the A horizon, such as clay, salts, and iron."