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

My point is that we might be hitting bedrock on the subject of companies that can cash in on the AI buildout.

From Barron's • Jun. 5, 2026

The shape of the bedrock beneath the ice continues to influence how ice moves across the continent today.

From Science Daily • Jun. 4, 2026

The coal industry remains a bedrock of the Chinese economy, powering factories and homes.

From The Wall Street Journal • May 23, 2026

Abigail herself reported that all the bedrock Federalist enclaves of New England were taken by surprise: “the whole community were like a flock of frightened pigions; nobody had their story ready.”

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis