radiation

[ rey-dee-ey-shuhn ]

noun

1. Physics.
   1. the process in which energy is emitted as particles or waves.
   2. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and absorbed by another body.
   3. the energy transferred by these processes.
2. the act or process of radiating.
3. something that is radiated.
4. radial arrangement of parts.

radiation

/ ˌreɪdɪˈeɪʃən /

noun

1. physics
   1. the emission or transfer of radiant energy as particles, electromagnetic waves, sound, etc
   2. the particles, etc, emitted, esp the particles and gamma rays emitted in nuclear decay
2. Also calledradiation therapy med treatment using a radioactive substance
3. anatomy a group of nerve fibres that diverge from their common source
4. See adaptive radiation
5. the act, state, or process of radiating or being radiated
6. surveying the fixing of points around a central plane table by using an alidade and measuring tape

radiation

/ rā′dē-ā′shən /

1. 1. Streams of photons, electrons, small nuclei, or other particles. Radiation is given off by a wide variety of processes, such as thermal activity, nuclear reactions (as in fission), and by radioactive decay.
   2. The emission or movement of such particles through space or a medium, such as air.
2. The use of such energy, especially x-rays, in medical diagnosis and treatment.

radiation

1. Energy sent out in the form of particles or waves . ( See alpha radiation , beta radiation , blackbody , cosmic rays , electromagnetic radiation , fluorescence , gamma radiation , photon , and quanta .)

Derived Forms

• ˌradiˈational, adjective

Other Words From

• radi·ation·al adjective
• anti·radi·ation adjective
• inter·radi·ation noun
• nonra·di·ation noun

Word History and Origins

Origin of radiation¹

First recorded in 1545–55; from Latin radiātiōn-, stem of radiātiō “beam, gleam, shine”; equivalent to radiate + -ion

Example Sentences

Objects that go outside, like a suit or scientific kit, are affected by the strong radiation of space.

From BBC

“Radiation forms free radicals on the surface, and they react with oxygen inside the space station, creating a metallic smell,” she says.

From BBC

‘I’m very excited to finally be done,’ she said of radiation.

From Los Angeles Times

A gamma, for example, is a type of radiation.

From BBC

But it should not be confused with external radiotherapy where they blast tumours from outside the body with radiation.

From BBC

Related Words

• radioactivity