Definition of radon in English:



mass noun
  • The chemical element of atomic number 86, a rare radioactive gas belonging to the noble gas series.

    Radon is a product of the radioactive decay of radium and is used as a source of alpha particles in radiotherapy. Small quantities of the gas are also emitted naturally from the ground in granite-rich areas

    • ‘All the areas had previously been thought to be safe from high levels of seeping radon, which comes out of the ground and gathers in enclosed spaces.’
    • ‘That is roughly half the annual dose from inhaled radon and its decay products in a typical single family home in the United States.’
    • ‘A review of over 11 studies in uranium miners attributed an observed increase in lung cancer to radon and its progeny and not to uranium.’
    • ‘The ground in some parts of the country releases radon, a radioactive gas that can cause cancer.’
    • ‘As the pressure in a building is slightly lower than the pressure outdoors, radon will be drawn from the ground into the building.’


Early 20th century: from radium, on the pattern of argon.