radiation

the treatment of disease, especially cancer, by exposure to a radioactive substance

the act of spreading outward from a central source

a radial arrangement of nerve fibers connecting different parts of the brain

the spread of a group of organisms into new habitats

energy that is radiated or transmitted in the form of rays or waves or particles

the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay

syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions)