linchpin

noun

linch·​pin ˈlinch-ˌpin How to pronounce linchpin (audio)
variants or less commonly
1
: a locking pin inserted crosswise (as through the end of an axle or shaft)
2
: one that serves to hold together parts or elements that exist or function as a unit
the linchpin in the defense's case

Did you know?

In his 1857 novel, Tom Brown’s School Days, Thomas Hughes describes the “cowardly” custom of “taking the linch-pins out of the farmers’ and bagmens’ gigs at the fairs.” The linchpin in question held the wheel on the carriage, and removing it made it likely that the wheel would come off as the vehicle moved. Such a pin was called a lynis in Old English; Middle English speakers added pin to form lynspin. By the early 20th century, English speakers were using linchpin for anything as critical to a complex situation as a linchpin is to a wagon, as when Winston Churchill, in 1930, wrote of Canada and the role it played in the relationship between Great Britain and the United States, that “no state, no country, no band of men can more truly be described as the linchpin of peace and world progress.”

Examples of linchpin in a Sentence

This witness is the linchpin of the defense's case.
Recent Examples on the Web
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.
The Joshua tree is cherished for its distinctive silhouette and singular role as a linchpin of the Mojave Desert ecosystem. Grace Toohey, Los Angeles Times, 30 May 2025 Despite economic realities, Trump touts coal as a linchpin of his second-term policies. Michael Hawthorne, Chicago Tribune, 25 May 2025 What’s more, the tariffs and the president’s disregard for the traditions of international diplomacy have damaged the status of the dollar and the U.S. Treasury bond as linchpins of the world financial system. Jeff Sommer, New York Times, 2 May 2025 In the first instance, this means being able to reinforce Poland, which by reason of size, location, and topography is both the eastern linchpin of European defense and the ideal base from which to counter Russian threats against the Baltic states and the continent’s southeast. Barry R. Posen, Foreign Affairs, 21 Apr. 2025 See All Example Sentences for linchpin

Word History

Etymology

Middle English lynspin, from lyns linchpin (from Old English lynis) + pin; akin to Middle High German luns linchpin

First Known Use

13th century, in the meaning defined at sense 1

Time Traveler
The first known use of linchpin was in the 13th century

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Cite this Entry

“Linchpin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/linchpin. Accessed 6 Jun. 2025.

Kids Definition

linchpin

noun
linch·​pin ˈlinch-ˌpin How to pronounce linchpin (audio)
: a pin inserted crosswise through something (as the end of an axle or shaft) to keep things in place
Last Updated: - Updated example sentences
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