Radiation

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 some forms of cancer and other diseases; severe exposure can cause death within hours

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

(medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance

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

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

the act of spreading outward from a central source

the spread of a group of organisms into new habitats