Definition of radiation noun from the Oxford Advanced Learner's Dictionary



    BrE BrE//ˌreɪdiˈeɪʃn//
    ; NAmE NAmE//ˌreɪdiˈeɪʃn//
    Energy and physical forces, The Earth and the atmosphere
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  1. 1[uncountable, countable] powerful and very dangerous rays that are sent out from radioactive substances high levels/doses of radiation that damage cells the link between exposure to radiation and childhood cancer a radiation leak from a nuclear power station radiation sickness the radiations emitted by radium See related entries: Energy and physical forces
  2. 2[uncountable] heat, energy, etc. that is sent out in the form of rays ultraviolet radiation electromagnetic radiation from power lines See related entries: The Earth and the atmosphere
  3. 3(also radiation therapy) [uncountable] the treatment of cancer and other diseases using radiation compare chemotherapy, radiotherapy
  4. Word Originlate Middle English (denoting the action of sending out rays of light): from Latin radiatio(n-), from radiare ‘emit rays’, from radius ‘ray, spoke’.Extra examples Nuclear testing has exposed millions of people to radiation. Ozone protects the Earth from harmful ultraviolet radiation. Patients receive high doses of radiation during cancer treatment. The counter showed high levels of radiation. The ozone layer absorbs solar radiation. fluctuations in the cosmic microwave background radiation radiation from computer screens radiation leaking from nuclear power stations the threat of radiation leaks
See the Oxford Advanced American Dictionary entry: radiation