linchpin

noun

linch·​pin ˈlinch-ˌpin 

variants or less commonly lynchpin

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 blackguard 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 gig 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

On Tuesday, Shasta and Oroville, the two largest reservoirs in California, and linchpins of the water supply for more than 20 million people from the Bay Area to San Diego, each were 84% full. —Paul Rogers, The Mercury News, 27 Feb. 2024

Of the 16 House districts won by Mr. Biden but currently in Republican hands, five are in California, making the state a linchpin of the party’s hopes of retaking the chamber, where Republicans currently hold a three-seat majority. —Jonathan Weisman, New York Times, 3 Mar. 2024

In the heart of California, at the place where two great rivers converge beneath the Tule fog, lies the linchpin of one of the largest water supply systems in the world. —Hayley Smith, Los Angeles Times, 29 Feb. 2024

Emerging Economies Steering Global Shipping Emerging economies, particularly in Asia, are increasingly becoming the linchpins of maritime trade growth. —Frank Holmes, Forbes, 20 Feb. 2024

And that brings us to a linchpin of Kennedy’s efforts to change Cadiz’s image from water profiteer to responsible steward of a precious, and increasingly scarce, natural resource. —Michael Hiltzik, Los Angeles Times, 25 Jan. 2024

In a world inundated with choices and overflowing with information, brand recognition, and a unified, multi-channel messaging strategy are re-emerging as the linchpins of successful marketing. —Dara A. Busch, Fortune, 11 Mar. 2024

Yet, digital advancements, such as automation, are quickly becoming linchpins in addressing slow, manual, and error-prone tasks hindering procurement efficiency. —Forbes, 1 Mar. 2024

Stephenie Stewart, the longtime manager whom McClelland described as the linchpin of the whole place, has luckily stuck around to keep the show running and to maintain the vibe after the ownership change. —Allison Dikanovic, Kansas City Star, 21 Feb. 2024

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

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Kids Definition

linchpin

noun

linch·​pin ˈlinch-ˌpin 

: a pin inserted crosswise through something (as the end of an axle or shaft) to keep things in place