# radiation

Pronunciation: say "ray-dee-AY-shuhn" US/UK /ˌɹeɪ.diˈeɪ.ʃən/, AUS /ˌɹæɪ.diˈæɪ.ʃən/

## Noun

1. Energy emitted by radioactive materials as their atoms break down.
   - Simple: Energy given off by materials that are radioactive.
   - _Geiger counters click faster as the radiation grows more intense._
   - _Prolonged exposure to radiation can damage living cells._
2. Ellipsis of electromagnetic radiation. — Ellipsis of electromagnetic radiation.
   - Simple: Short for electromagnetic radiation. Used when the longer name is already clear from context.
   - _Radio antennas detect radiation across a wide range of wavelengths._
   - _Infrared radiation warms your skin even on a cloudy day._
3. The movement of energy through space by means of electromagnetic waves, requiring no material medium.
   - Simple: A way that heat or energy travels through space as waves, with nothing in between.
   - _Unlike conduction, radiation can carry heat across the vacuum of space._
   - _A thermos slows heat loss by reducing both convection and radiation._
4. The process of emitting waves or particles outward from a source.
   - Simple: The sending out of waves or tiny particles from something.
   - _The radiation of heat from the engine could be measured with infrared sensors._
   - _Sunspots influence the radiation of charged particles into the solar wind._
5. The spreading outward of something from a central point or surface, as rays of light diverge.
   - Simple: The spreading out of something from a center point, like rays of light.
   - _The radiation of nerve fibers from the spinal cord forms a complex network._
   - _Map designers illustrated the radiation of trade routes from the ancient capital._
6. A rapid branching of one ancestral species into many distinct new forms.
   - Simple: A fast spread of one species into many new and different kinds.
   - _The adaptive radiation of cichlid fish produced hundreds of species in a single lake._
   - _Biologists trace the radiation of flowering plants to a burst of new pollinators._

## Origin

Borrowed from Latin "radiatio" (stem "radiationis"). By surface analysis, it can be seen as "radiate" plus the suffix "-ion."

Source: DictionaryAI, https://dictionaryai.com/define/radiation (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).