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

"It's one of my bedrock beliefs that our laws should be applied fairly, and I simply do not believe that was what happened in this case," he added.

From BBC • May 16, 2026

"GreenDrill really demonstrated that, if you can logistically pull it off, there is the technology available to drill down to the bedrock and there's an analytical toolkit to then analyze it," Briner says.

From Science Daily • Apr. 18, 2026

Freedom of navigation has been a bedrock U.S. principle for centuries.

From The Wall Street Journal • Apr. 8, 2026

But China, like other developing countries, has said it wants this rule to "remain the bedrock of the WTO".

From Barron's • Mar. 26, 2026

The Uzumark wasn’t a single, massive subterranean channel, but an intricate network of waterways that carved their way through the valley bedrock.

From "Strange the Dreamer" by Laini Taylor