Geology. unbroken solid rock, overlaid in most places by soil or rock fragments.
bottom layer; lowest stratum.
any firm foundation or basis: Technical courses will be founded on a bedrock of sound, general education so as to produce a well-rounded engineer.
the fundamental principles, as of a teaching, belief, or science: Let's strip away the cant and get down to bedrock.


basic; fundamental.

Origin of bedrock

An Americanism dating back to 1840–50; bed + rock1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for bedrock

ground, substratum, base, bottom

Examples from the Web for bedrock

Contemporary Examples of bedrock

Historical Examples of bedrock

  • Such a belief was indeed the bedrock of mediaeval political thought.

  • All superficial accumulations were swept away, and the bedrock was exposed.

    A Tramp Abroad, Complete

    Mark Twain (Samuel Clemens)

  • The bedrock on which they fought was slippery where ice had formed in the crevices.

    A Man to His Mate

    J. Allan Dunn

  • Here was always the reminder of that bedrock principle of his thought.

    Ruskin Relics

    W. G. Collingwood

  • He is going, said Old Mole, to discover the bedrock of life and live on it.

    Old Mole

    Gilbert Cannan

British Dictionary definitions for bedrock



the solid unweathered rock that lies beneath the loose surface deposits of soil, alluvium, etc
basic principles or facts (esp in the phrase get down to bedrock)
the lowest point, level, or layer
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 bedrock

also bed-rock, 1850, from bed (n.) + rock (n.). Figurative use by 1869; as an adjective by 1881.

Online Etymology Dictionary, © 2010 Douglas Harper

bedrock in Science



The solid rock that lies beneath the soil and other loose material on the Earth's surface.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.