O-ring
[ oh-ring ]
/ ˈoʊˌrɪŋ /
noun
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.
Origin of O-ring
First recorded in 1945–50
British Dictionary definitions for o-ring
O-ring
noun
a rubber ring used in machinery as a seal against oil, air, etc