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

The bedrock of a review is how the referee describes the incident to the VAR.

From BBC • Apr. 15, 2026

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

From The Wall Street Journal • Apr. 8, 2026

It became the bedrock upon which Palantir built its Artificial Intelligence Platform.

From MarketWatch • Apr. 4, 2026

Whether it’s Eddie, a friend McCarthy met in high school who resides in Alto, Texas, or Larry, a buddy in Austin, honesty and confession form the bedrock of true male intimacy.

From Los Angeles Times • Mar. 25, 2026

That is still a bedrock value in Levittown—work—even as teens in higher-end zip codes have moved on to unpaid endeavors to further augment their credentials.

From "Drama High" by Michael Sokolove