radiation

US /ˌreɪ.diˈeɪ.ʃən/
UK /ˌreɪ.diˈeɪ.ʃən/
"radiation" picture
1.

the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization

:
Exposure to high levels of radiation can be harmful.
The sun emits various forms of radiation, including ultraviolet light.
2.

the divergence of light or other electromagnetic radiation from a central point

:
The radiation of heat from the fireplace warmed the room.
The study focused on the radiation patterns of antennas.