Radionuclide
Cancer
(RAY-dee-oh-NOO-klide) An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable. Radionuclides may occur in nature or be made in a laboratory. In medicine, they are used in imaging tests and in treatment. Also called radioisotope.
Nuclear Physics
A radioactive nuclide. An unstable isotope of an element that decays or disintegrates spontaneously, emitting radiation.
- — Glossary of Nuclear Science Terms retrieved 2014-05-20