trunnion

noun

trun·​nion ˈtrən-yən How to pronounce trunnion (audio)
: a pin or pivot on which something can be rotated or tilted
especially : either of two opposite gudgeons on which a cannon is swiveled

Examples of trunnion in a Sentence

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.
Use grease on choke tube threads and on the trunnions or hinge-pin where the barrels pivot on a break-action, and on the knuckle, the half-round piece on some break-action frames that bear on the forend iron. Phil Bourjaily, Field & Stream, 27 Feb. 2023 Chicago’s first trunnion bascule bridge — is built over the North Branch of the Chicago River. Chicago Tribune, 26 June 2022 The lane closure is scheduled from Sept. 28 - Oct. 4 as construction crews reconnect the median barrier and wrap up from the trunnion project. oregonlive, 25 Sep. 2020

Word History

Etymology

French trognon core, stump

First Known Use

circa 1625, in the meaning defined above

Time Traveler
The first known use of trunnion was circa 1625

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Cite this Entry

“Trunnion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trunnion. Accessed 11 Sep. 2025.

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