Meaning of RADIATION in English

RADIATION

/ ˌreɪdiˈeɪʃn; NAmE / noun

1.

[ U , C ] 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

2.

[ U ] heat, energy, etc. that is sent out in the form of rays :

ultraviolet radiation

electromagnetic radiation from power lines

3.

(also ˌradiˈation therapy ) [ U ] the treatment of cancer and other diseases using radiation

—compare chemotherapy , radiotherapy

••

WORD ORIGIN

late Middle English (denoting the action of sending out rays of light): from Latin radiatio(n-) , from radiare emit rays, from radius ray, spoke.

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.