illumination

American  

[ih-loo-muh-ney-shuhn] / ɪˌlu məˈneɪ ʃən /

noun

1. an act or instance of illuminating. illuminating.

2. the fact or condition of being illuminated.

3. a decoration of lights, usually colored lights.

4. Sometimes illuminations. an entertainment, display, or celebration using lights as a major feature or decoration.

5. intellectual or spiritual enlightenment.

   Synonyms:

   wisdom, insight, revelation, knowledge

6. Also called illuminance.  Also called intensity of illumination.  Optics. the intensity of light falling at a given place on a lighted surface; the luminous flux incident per unit area, expressed in lumens per unit of area.

7. a supply of light.

   a source of illumination.

8. decoration of a manuscript or book with a painted design in color, gold, etc.

9. a design used in such decoration.

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illumination British  

/ ɪˌluːmɪˈneɪʃən /

noun

1. the act of illuminating or the state of being illuminated

2. a source of light

3. (often plural) a light or lights, esp coloured lights, used as decoration in streets, parks, etc

4. spiritual or intellectual enlightenment; insight or understanding

5. the act of making understood; clarification

6. decoration in colours, gold, or silver used on some manuscripts or printed works

7. physics another name (not in technical usage) for illuminance

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Other Word Forms

• illuminational adjective
• nonillumination noun
• preillumination noun
• reillumination noun

Etymology

Origin of illumination

First recorded in 1300–50; Middle English, from Medieval Latin illūminātiōn-, stem of illūminātiō “spiritual enlightenment,” from Latin: “illustriousness, glory”; illuminate ( def. ), -ion ( def. )

Example Sentences

The framework provides an accurate description of how these materials absorb light and how their electronic structure behaves under illumination.

From Science Daily • Mar. 16, 2026

But generating enough heat from harder to capture wavelengths has traditionally required thick absorbing materials or very bright illumination, making such detectors bulky and slow.

From Science Daily • Mar. 4, 2026

The Plaza features quaint Spanish village scenery built out of its side walls with background illumination that glows pink and then deep purple, emulating a setting sun as the lights go down.

From Los Angeles Times • Dec. 9, 2025

Owenna Griffiths, editor of Today, said: "In a rapidly changing world, this year's guest editors will help bring illumination and understanding".

From BBC • Nov. 23, 2025

“Having seen nothing but kerosene lamps for illumination, this was like getting a sudden vision of Heaven.”

From "The Devil in the White City" by Erik Larson

Related Words

• brightness