n.
1.energy that is radiated or transmitted in the form of rays or waves or particles
2.the act of spreading outward from a central source
3.syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions)
4.the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
5.the spread of a group of organisms into new habitats
6.a radial arrangement of nerve fibers connecting different parts of the brain
7.(medicine) the treatment of disease (especially cancer) by exposure to radiation from a radioactive substance
Idiom of the Day
at the appointed hour
at the time that has been decided
At the appointed hour, the team arrived at the stadium.
