noun Uncommon

keystone

KEE-stohn

Keystone (noun) means the central wedge-shaped stone at the top of an arch that locks the other stones in place. Example: “Remove the keystone and the whole arch collapses.”

noun

The central wedge-shaped stone at the top of an arch that locks the other stones in place.

"Remove the keystone and the whole arch collapses."

The central element that everything else depends on or is built around.

"Trust is the keystone of any good relationship."

How to use keystone

Learner’s notes

In plain EnglishLiterally the locking stone at the top of an arch, or figuratively the single most essential part of a plan, argument, or system.

Common pairings

keystone of the arch keystone species keystone policy

Word forms

keystoned past tense, keystones plural, keystones singular

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Fill the gap

Can you complete this real example?

Remove the _____ and the whole arch collapses.

Etymology

From "key" (in the sense of a locking piece) and "stone" — the stone that locks an arch together.

Synonyms

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key anchor backbone linchpin headstone mainstay lynchpin

Related words

back stop important major main central key island

Rhymes for keystone

one bone done gone none tone lone hone cone zone stone phone

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Frequently asked questions

What does “keystone” mean?

The word “keystone” means the central wedge-shaped stone at the top of an arch that locks the other stones in place. In plain terms, literally the locking stone at the top of an arch, or figuratively the single most essential part of a plan, argument, or system.

How do you pronounce “keystone”?

“Keystone” is pronounced KEE-stohn (/ˈkiː.stəʊn/ in IPA).

How do you use “keystone” in a sentence?

Here is “keystone” used in a sentence: “Remove the keystone and the whole arch collapses.”

What part of speech is “keystone”?

“Keystone” is a noun.

Is “keystone” a common word?

“Keystone” is an uncommon word in modern English.

How many meanings does “keystone” have?

“Keystone” has 2 distinct senses listed in this dictionary. The most common is: the central wedge-shaped stone at the top of an arch that locks the other stones in place.

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