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.

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O-ring British  

noun

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

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Etymology

Origin of O-ring

First recorded in 1945–50

Example Sentences

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

You can use copper press fittings that seal the joint with a rubber O-ring.

From Seattle Times • May 15, 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