"A unit of absorbed dose of radiation; it represents the absorption of 100 ergs of nuclear (or ionizing) radiation per gram of absorbing material, such as body tissue". (Glasstone, The Effects of Nuclear Weapons, 3rd Ed., 1977, Glossary, p. 638)
B. Wayne Blanchard, Guide To Emergency Management and Related Terms, Definitions, Concepts, Acronyms, Organizations, Programs, Guidance, Executive Orders & Legislation, A Tutorial on Emergency Management, Broadly Defined, Past and Present, B. Wayne Blanchard, USA 2007 (Last Modified 2008). http://training.fema.gov/EMIWeb/edu/docs/terms%20a nd%20definitions/Terms%20and%20Definitions.pdf, (Emr Mgt/ ND and Other Dzstr - Amer) {11}