(n): (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs
(n): the act of spreading outward from a central source
(n): the act of emitting; causing to flow forth
(n): 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
(n): a pattern of symptoms indicative of some disease
(n): the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
(n): the release of electrons from parent atoms
(n): the spread of a group of organisms into new habitats
(n): a process existing in or produced by nature (rather than by the intent of human beings)
(n): process or result of distributing or extending over a wide expanse of space
(n): a radial arrangement of nerve fibers connecting different parts of the brain
(n): a structure that is part of the nervous system
(n): (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
(n): (medicine) the act of caring for someone (as by medication or remedial training etc.)