1
: the wedge-shaped piece at the crown of an arch that locks the other pieces in place see arch illustration
2
: something on which associated things depend for support
determination, a keystone of the puritan ethic—
L. S. Lewis
L. S. Lewis3
or keystone species
: a species of plant or animal that produces a major impact (as by predation) on its ecosystem and is considered essential to maintaining optimum ecosystem function or structure
Synonyms
Examples of keystone in a Sentence
Tourism is the city's economic keystone.
the keystone of his faith
Recent Examples on the Web
A number of useful tools have been included to help take the sting out of setup, such as 1.3x zoom, auto vertical keystone plus manual horizontal, vertical lens shift, 8-point corner adjustment, and auto-fit to screen.
—Paul Ridden, New Atlas, 2 Nov. 2024
This should be a warning flag for all because data analysis, be that software or hardware-related, is the keystone for most hacking activity.
—Davey Winder, Forbes, 21 Oct. 2024
Optical zoom and vertical lens shift, along with autofocus, keystone correction, screen fit and obstacle avoidance, also help make positioning and setup a breeze.
—New Atlas, 10 Oct. 2024
Catch up quick: The U.S. Supreme Court ruled in a bribery case involving a former Portage, Indiana, mayor that there is a difference between a bribe and a gratuity, essentially nixing a keystone corruption law for the federal government.
—Justin Kaufmann, Axios, 9 July 2024
See all Example Sentences for keystone 
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Paul Ridden, New Atlas, 2 Nov. 2024
This should be a warning flag for all because data analysis, be that software or hardware-related, is the keystone for most hacking activity.
—Davey Winder, Forbes, 21 Oct. 2024
Optical zoom and vertical lens shift, along with autofocus, keystone correction, screen fit and obstacle avoidance, also help make positioning and setup a breeze.
—New Atlas, 10 Oct. 2024
Catch up quick: The U.S. Supreme Court ruled in a bribery case involving a former Portage, Indiana, mayor that there is a difference between a bribe and a gratuity, essentially nixing a keystone corruption law for the federal government.
—Justin Kaufmann, Axios, 9 July 2024
See all Example Sentences for keystone
Articles Related to keystone
Dictionary Entries Near keystone
Cite this Entry
“Keystone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/keystone. Accessed 26 Nov. 2024.
Copy CitationKids Definition
keystone
noun
key·stone
ˈkē-ˌstōn 
1
: the wedge-shaped piece at the top of an arch that locks the other pieces in place
2
: something on which other things depend
Love words? Need even more definitions?
Merriam-Webster unabridged
Share