noun energy that is radiated or transmitted in the form of rays or waves or particles.
noun the act of spreading outward from a central source.
noun syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions).
— synonyms: radiation_sickness, radiation_syndrome
noun the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay.
— synonyms: radioactivity
noun the spread of a group of organisms into new habitats.
noun a radial arrangement of nerve fibers connecting different parts of the brain.
noun (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance.
— synonyms: radiotherapy, radiation_therapy, actinotherapy, irradiation