radiation Meaning, Definition & Usage

1. noun energy that is radiated or transmitted in the form of rays or waves or particles
   
2. noun the act of spreading outward from a central source
   
3. noun 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
   radiation sickness; radiation syndrome.
   
   • he was suffering from radiation
4. noun the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
   radioactivity.
   
5. noun the spread of a group of organisms into new habitats
   
6. noun a radial arrangement of nerve fibers connecting different parts of the brain
   
7. noun (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
   radiotherapy; irradiation; radiation therapy; actinotherapy.
   

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