名词

1. 辐射物；放射物
Radiation consists of very small particles of a radioactive substance. Large amounts of radiation can cause illness and death.

2. 辐射能;放射能;（尤指）热能
Radiation is energy, especially heat, that comes from a particular source.

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

Synonym: radiotherapyradiation therapyactinotherapyirradiation

2. the act of spreading outward from a central source

3. a radial arrangement of nerve fibers connecting different parts of the brain

4. the spread of a group of organisms into new habitats

5. energy that is radiated or transmitted in the form of rays or waves or particles

6. the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay

Synonym: radioactivity

7. 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

e.g. he was suffering from radiation

Synonym: radiation sicknessradiation syndrome