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O-ring

American  
[oh-ring] / ˈoʊˌrɪŋ /

noun

  1. a ring of pliable material, as rubber or neoprene, used as a gasket: the failure of an O-ring caused the explosion that destroyed the space shuttle Challenger in 1986.


O-ring British  

noun

  1. a rubber ring used in machinery as a seal against oil, air, etc

"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

Etymology

Origin of O-ring

First recorded in 1945–50

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Ms. Vaughan argues that, over time, NASA’s work culture privileged risk-taking, such as launching at temperatures known to cause O-ring damage.

From The Wall Street Journal Nov. 28, 2025

The company said an O-ring in the antilock brake motor shaft can lose sealing strength over time due to the presence of moisture, dirt and dissolved metals in the brake fluid, causing leaks.

From Washington Times Sep. 27, 2023

It's an example of what economists call an O-ring technology, harking back to the rubber seals whose catastrophic failure caused the Space Shuttle Challenger disaster in 1986.

From Salon Dec. 18, 2022

The fresh black-eyed pea is a wonder of markings all its own, with that deep purple-black O-ring in the same spot on every tiny little pale green pea.

From New York Times Sep. 15, 2021

Over in the production group at ATK, a whole different division, they sometimes had trouble with a machine that inspected the booster rockets’ O-ring grooves to make sure there was no corrosion.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

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