Meaning & Definition of Radiation in English

1. Energy that is radiated or transmitted in the form of rays or waves or particles

2. The act of spreading outward from a central source

3. 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

• "He was suffering from radiation"

4. The spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay

5. The spread of a group of organisms into new habitats

6. A radial arrangement of nerve fibers connecting different parts of the brain

7. (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance