bedrock

American  

[bed-rok] / ˈbɛdˌrɒk /

noun

1. Geology. unbroken solid rock, overlaid in most places by soil or rock fragments.

2. bottom layer; lowest stratum.

3. 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.

4. the fundamental principles, as of a teaching, belief, or science.

   Let's strip away the cant and get down to bedrock.

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adjective

1. basic; fundamental.

bedrock British  

/ ˈbɛdˌrɒk /

noun

1. the solid unweathered rock that lies beneath the loose surface deposits of soil, alluvium, etc

2. basic principles or facts (esp in the phrase get down to bedrock )

3. the lowest point, level, or layer

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bedrock Scientific  

/ bĕd′rŏk′ /

1. The solid rock that lies beneath the soil and other loose material on the Earth's surface.

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Etymology

Origin of bedrock

An Americanism dating back to 1840–50; bed + rock ¹

Explanation

Bedrock is the hard layer of rock beneath looser rocks and soil. In some places, the bedrock is exposed, while in others it lies deep underground. A geologist who's interested in studying the bedrock in different areas might have to dig through the various layers of soil to reach that bedrock. You can also use the word in a figurative way, to mean "the heart of the matter," or "the basic, fundamental principles." For example, you might say that fairness and freedom is the bedrock of a good government. The word combines bed — here meaning "plot of land" — and rock.

Example Sentences

Gregg, Mandery writes, “created the bedrock principles of modern death penalty jurisprudence: that a non-arbitrary death penalty satisfies the Constitution and that the requirement of non-arbitrariness could be satisfied by Georgia’s approach.”

From Slate • Jun. 8, 2026

His voice echoed in the damp tunnel where the spent nuclear fuel will be buried in holes drilled into the bedrock, where it will remain harmfully radioactive for thousands of years.

From Barron's • Jun. 1, 2026

Enveloping all of this is his bedrock conviction that all men are created equal.

From The Wall Street Journal • Jun. 1, 2026

Researchers found that the glacier lost not only this floating ice tongue, but also a large section of grounded ice resting on a flat area of bedrock.

From Science Daily • May 19, 2026

Phineas is the foreman of a track construction gang that is in the process of blasting a railroad right-of-way through granite bedrock near the small town of Cavendish, Vermont.

From "Phineas Gage" by John Fleischman