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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.

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

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

The shuttle’s rockets contained a series of rubber O-ring gaskets, and he worried that low temperatures could cause them to stiffen, allowing fuel to escape and potentially causing the rocket to explode.

From Seattle Times • Mar. 9, 2021

The Celestial bronze O-ring slipped out of Leo’s pliers and slid into the depths of the crawl space.

From "Blood of Olympus" by Rick Riordan

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