xenon

noun

xe·​non ˈzē-ˌnän  ˈze- 

: a heavy colorless and relatively inert gaseous element that occurs in air as about one part in 20 million and is used especially in specialized electric lamps (such as flash tubes) and in scientific research see Chemical Elements Table

Examples of xenon in a Sentence

Recent Examples on the Web

The experiment relies on detecting the faint interactions between hypothetical dark matter particles and atoms of liquid xenon, a noble gas chosen for its purity and stability. —Kapil Kajal, Interesting Engineering, 2 Oct. 2025

An ion engine works by using an inert gas as a propellant; often this gas is xenon, but Takahashi used argon. —Keith Cooper, Space.com, 16 Sep. 2025

Those criticisms take for granted that xenon actually works—but scientists aren’t so sure. —Alex Hutchinson, Outside, 15 Sep. 2025

The World Anti-Doping Agency has banned xenon in sports, and although mountaineering isn’t formally regulated, the International Climbing and Mountaineering Federation recently put out a statement poo-pooing its use. —Popular Science Team, Popular Science, 2 July 2025

Word History

Etymology

Greek, neuter of xenos strange

First Known Use

1898, in the meaning defined above

Kids Definition

xenon

noun

xe·​non ˈzē-ˌnän  ˈzen-ˌän 

: a heavy colorless gaseous element that occurs in air in minute quantities and is used especially in specialized electric lamps see element

Medical Definition

xenon

noun

xe·​non ˈzē-ˌnän  ˈzen-ˌän 

: a heavy, colorless, and relatively inert gaseous element that occurs in air as about one part in 20 million by volume

—symbol Xe see Chemical Elements Table