A general term applicable to all atomic forms of the elements. The term is often [erroneously used as a synonym for "isotope," which properly has a more limited definition. Whereas isotopes are various forms of a single element (hence, a family of radionuclides) and all have the same atomic members. Nuclides comprise all the isotopic forms of all the elements.
(DOE. TRADE Glossary and Acronyms of Emergency Management Terms. ORAU 91/K-37. November 1991.)