(medicine) the treatment of disease (especially cancer) by exposure to radiation from 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); low doses cause diarrhea and nausea and vomiting and sometimes loss of hair; greater exposure can cause sterility and cataracts and;
