What does radiation mean?

Definitions for radiation
ˌreɪ diˈeɪ ʃənra·di·a·tion

This dictionary definitions page includes all the possible meanings, example usage and translations of the word radiation.

Princeton's WordNet

  1. radiationnoun

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

  2. radiationnoun

    the act of spreading outward from a central source

  3. radiation sickness, radiation syndrome, radiationnoun

    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. radiation, radioactivitynoun

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

  5. radiationnoun

    the spread of a group of organisms into new habitats

  6. radiationnoun

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

  7. radiotherapy, radiation therapy, radiation, actinotherapy, irradiationnoun

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


  1. radiationnoun

    The shooting forth of anything from a point or surface, like the diverging rays of light; as, the radiation of heat.

  2. radiationnoun

    The process of radiating waves or particles.

  3. radiationnoun

    The transfer of energy via radiation (as opposed to convection or conduction)

  4. radiationnoun

    Radioactive energy

  5. Etymology: From radiatio.

Samuel Johnson's Dictionary

  1. Radiationnoun

    Etymology: radiatio, Lat. radiation, Fr.

    We have perspective houses, where we make demonstrations of all lights and radiations, and of all colours. Francis Bacon.

    Should I say I liv’d darker than were true,
    Your radiation can all clouds subdue,
    But one; ’tis best light to contemplate you. John Donne.

    Sound paralleleth in many things with the light, and radiation of things visible. Francis Bacon, Natural History.


  1. radiation

    Radiation is the emission or transmission of energy in the form of particles or waves through space or through a material medium. This includes electro-magnetic radiation such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation, as well as particle radiation such as alpha radiation, beta radiation, and neutron radiation.

Webster Dictionary

  1. Radiationnoun

    the act of radiating, or the state of being radiated; emission and diffusion of rays of light; beamy brightness

  2. Radiationnoun

    the shooting forth of anything from a point or surface, like the diverging rays of light; as, the radiation of heat

  3. Etymology: [L. radiatio: cf. F. radiation.]


  1. Radiation

    In physics, radiation is a process in which energetic particles or energetic waves travel through a vacuum, or through matter-containing media that are not required for their propagation. Waves of a mass filled medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense. Radiation can be classified as either ionizing or non-ionizing according to whether it ionizes or does not ionize ordinary chemical matter. The word radiation is often colloquially used in reference to ionizing radiation, but the term radiation may correctly also refer to non-ionizing radiation as well. The particles or waves radiate from a source. This aspect leads to a system of measurements and physical units that are applicable to all types of radiation. Because radiation expands as it passes through space, and as its energy is conserved, the power of all types of radiation follows an inverse-square law in relation to the distance from its source. Both ionizing and non-ionizing radiation can be harmful to organisms and can result in changes to the natural environment. In general, however, ionizing radiation is far more harmful to living organisms per unit of energy deposited than non-ionizing radiation, since the ions that are produced, even at low radiation powers, have the potential to cause DNA damage. By contrast, most non-ionizing radiation is harmful to organisms only in proportion to the thermal energy deposited, and is conventionally considered harmless at low powers that do not produce a significant temperature rise. Ultraviolet radiation in some aspects occupies a middle ground, as it has some features of both ionizing and non-ionizing radiation. Although nearly all of the ultraviolet spectrum that penetrates the Earth's atmosphere is non-ionizing, this radiation does far more damage to many molecules in biological systems than can be accounted for by heating effects. These properties derive from ultraviolet's power to alter chemical bonds, even without having quite enough energy to ionize atoms.

U.S. National Library of Medicine

  1. Radiation

    Emission or propagation of electromagnetic energy (waves/rays), or the waves/rays themselves; a stream of electromagnetic particles (electrons, neutrons, protons, alpha particles) or a mixture of these. The most common source is the sun.

The Standard Electrical Dictionary

  1. Radiation

    The traveling or motion of ether waves through space. [Transcriber's note: The modern term corresponding to this definition is photons. The modern concept of radiation also includes particles-- neutrons, protons, alpha (helium) and beta (electrons) rays and other exotic items.]

Editors Contribution

  1. Radiationadjective

    Radiation means emitting of heat energy through electromagnetic waves.

    The sun emits radiation.

    Submitted by chandusreddy007 on January 31, 2022  

British National Corpus

  1. Nouns Frequency

    Rank popularity for the word 'radiation' in Nouns Frequency: #2018

How to pronounce radiation?

How to say radiation in sign language?


  1. Chaldean Numerology

    The numerical value of radiation in Chaldean Numerology is: 8

  2. Pythagorean Numerology

    The numerical value of radiation in Pythagorean Numerology is: 1

Examples of radiation in a Sentence

  1. Arizona Department:

    Uranium naturally occurs in the rocks of Grand Canyon National Park. A recent survey of the Grand Canyon National Park's museum collection facility found radiation levels at' background' levels -- the amount always present in the environment -- and below levels of concern for public health and safety. There is no current risk to the public or Park employees.

  2. Rebecca Smith-Bindman:

    Everything we do in medicine involves trade-offs, the risks of radiation are real, and radiation leads to cancer. I think the data are quite compelling and not that hard to understand.

  3. Otis Brawley:

    You get your breast surgeons and your breast radiation oncologist and your breast medical oncologist, and they treat the breast cancer, and then you get the head-neck oncologists, including the radiation oncologist and the head-neck medical oncologist, and they treat the head and neck cancer, now, those two groups of people are going to have to talk to each other, and they’re going to have to work to coordinate with each other. But you don’t treat the patient differently other than that coordination.


    -reggae and radiologic technology-what's the connection?I often forget that I alone occupies this most enviable position. for over 53 years to date I have been working and training others in the field of -medical radiation technology. saving lives is what I do best. reggae is my creation and I am the one who brought it into the field of medical radiology. I remain board certified in several countries.the music is a healing force during many a medical procedure.

  5. Katherine Raymond:

    They did another biopsy then and determined it was myoepithelial carcinoma, an extremely rare cancer thats very serious, its extremely uncommon in children. When we were told about Fionahs condition, doctors said it was very rare and she would be facing an uphill battle. They told us she would need chemo, radiation and more surgery. They told us she might not live to see her first birthday which devastated us.

Popularity rank by frequency of use


Translations for radiation

From our Multilingual Translation Dictionary

Get even more translations for radiation »


Find a translation for the radiation definition in other languages:

Select another language:

  • - Select -
  • 简体中文 (Chinese - Simplified)
  • 繁體中文 (Chinese - Traditional)
  • Español (Spanish)
  • Esperanto (Esperanto)
  • 日本語 (Japanese)
  • Português (Portuguese)
  • Deutsch (German)
  • العربية (Arabic)
  • Français (French)
  • Русский (Russian)
  • ಕನ್ನಡ (Kannada)
  • 한국어 (Korean)
  • עברית (Hebrew)
  • Gaeilge (Irish)
  • Українська (Ukrainian)
  • اردو (Urdu)
  • Magyar (Hungarian)
  • मानक हिन्दी (Hindi)
  • Indonesia (Indonesian)
  • Italiano (Italian)
  • தமிழ் (Tamil)
  • Türkçe (Turkish)
  • తెలుగు (Telugu)
  • ภาษาไทย (Thai)
  • Tiếng Việt (Vietnamese)
  • Čeština (Czech)
  • Polski (Polish)
  • Bahasa Indonesia (Indonesian)
  • Românește (Romanian)
  • Nederlands (Dutch)
  • Ελληνικά (Greek)
  • Latinum (Latin)
  • Svenska (Swedish)
  • Dansk (Danish)
  • Suomi (Finnish)
  • فارسی (Persian)
  • ייִדיש (Yiddish)
  • հայերեն (Armenian)
  • Norsk (Norwegian)
  • English (English)

Word of the Day

Would you like us to send you a FREE new word definition delivered to your inbox daily?

Please enter your email address:


Use the citation below to add this definition to your bibliography:


"radiation." Definitions.net. STANDS4 LLC, 2024. Web. 25 Apr. 2024. <https://www.definitions.net/definition/radiation>.

Discuss these radiation definitions with the community:

1 Comment
  • Capree Nail Gantzel
    Capree Nail Gantzel
    ? doesent make sense for my son.
    LikeReply9 years ago

Are we missing a good definition for radiation? Don't keep it to yourself...

Image or illustration of


Credit »

Free, no signup required:

Add to Chrome

Get instant definitions for any word that hits you anywhere on the web!

Free, no signup required:

Add to Firefox

Get instant definitions for any word that hits you anywhere on the web!

Browse Definitions.net


Are you a words master?

young tree
A subrogation
B urus
C sapling
D exponent

Nearby & related entries:

Alternative searches for radiation: