a pin inserted through the end of an axletree to keep the wheel on.
something that holds the various elements of a complicated structure together: The monarchy was the linchpin of the nation's traditions and society.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use linchpin in a sentence
The Higgs boson is the linchpin of the Standard Model and the key to why the double simplex arrangement makes sense.
None of them are experts in epidemiology — the study of how diseases affect populations, a linchpin of particulate matter research.The EPA Refuses to Reduce Pollutants Linked to Coronavirus Deaths | by Lisa Song and Lylla Younes | October 21, 2020 | ProPublica
In fact, building a sizable beauty was a linchpin of Kohl’s “Greatness Agenda” in 2014, with the company hoping beauty would grow from 2% of sales then to 5% in short order, helped by so-called “beauty concierges.”Kohl’s bets on more activewear, fewer store brands to finally get back to growth | Phil Wahba | October 20, 2020 | Fortune
The demonstration that something like a linchpin of modern metabolism could have emerged under mild, minimally demanding conditions therefore makes a prebiotic origin for the TCA cycle look more feasible, which the metal catalyst experiments did not.New Clues to Chemical Origins of Metabolism at Dawn of Life | John Rennie | October 12, 2020 | Quanta Magazine
The principal hotspot is the HBO Max streaming service, the linchpin in AT&T’s gigantic strategic shift toward video content.
At the moment, Yisrael Beiteinu is the linchpin of the coming rightist government.
Bolshevism was the linchpin that held all the other facets of conspiracy together.Soviet Communism’s Collapse Left America’s Far Right Without a Real Foe | Lee Siegel | April 12, 2012 | THE DAILY BEAST
It was one courier in particular that proved the linchpin in Sunday night's operation that killed the al Qaeda leader.Osama bin Laden's Courier: The Man Who Led the U.S. to bin Laden | Josh Dzieza | May 3, 2011 | THE DAILY BEAST
Civilian control is still the constitutional linchpin uniting defender and defended.
Upon inspection, the losses of the day were found to be one linchpin and one pair of pantaloons.
His famous monologue with his imaginary friend "linchpin" invariably brought the house down.Fanny Goes to War | Pat Beauchamp
Had he withdrawn some linchpin of ordinary conduct from the wheel on which the whole world revolves?The Tower of Oblivion | Oliver Onions
The drawbolt on a linchpin wagon usually has a head made in the form of the jaws of a wrench.Farm Mechanics | Herbert A. Shearer
The government had sent him in pursuit of a golden chariot, and he found more than the linchpin.Vitus Bering: the Discoverer of Bering Strait | Peter Lauridsen
British Dictionary definitions for linchpin
a pin placed transversely through an axle to keep a wheel in position
a person or thing regarded as an essential or coordinating element: the linchpin of the company
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012