the bed or stratum of earth or earthy material immediately under the surface soil.

Origin of subsoil

First recorded in 1790–1800; sub- + soil1
Also called undersoil. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for subsoil

land, dirt, terrain, shore, surface, coast, mud, clay, dust, turf, gravel, sand, clod, sod, muck, compost, deposit, mold, fill, marl

Examples from the Web for subsoil

Historical Examples of subsoil

British Dictionary definitions for subsoil



  1. Also called: undersoilthe layer of soil beneath the surface soil and overlying the bedrock
  2. (as modifier)a subsoil plough


(tr) to plough (land) to a depth below the normal ploughing level and so break up the subsoil
Derived Formssubsoiler, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for subsoil

1799, from sub- + soil (n.).

Online Etymology Dictionary, © 2010 Douglas Harper

subsoil in Science



In an ABC soil, the B horizon. The term was formerly used to mean the layer of earth below the humus or surface soil.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.