illumination

noun

il·​lu·​mi·​na·​tion i-ˌlü-mə-ˈnā-shən 

1

: the action of illuminating or state of being illuminated: such as

a

: spiritual or intellectual enlightenment

b(1)

: a lighting up

the illumination of the room

(2)

: decorative lighting or lighting effects

c

: decoration by the art of illuminating

a medieval manuscript with magnificent illumination

2

: the luminous flux per unit area on an intercepting surface at any given point

3

: one of the decorative features used in the art of illuminating or in decorative lighting

Synonyms of illumination

• explanation
• interpretation
• illustration

Examples of illumination in a Sentence

When taking photographs indoors, use a flash for illumination.

They traveled to the temple in search of spiritual illumination.

an old manuscript with beautiful illuminations

Recent Examples on the Web

This illumination covers both light visible to the human eye and longer wavelengths of light in the infrared and radio regions of the electromagnetic spectrum. —Robert Lea, Space.com, 17 Nov. 2025

Kill it with chlorine or grow it to save energy for room illumination. —Melissa Fleur Afshar, MSNBC Newsweek, 17 Nov. 2025

In an accelerated aging test, an unpassivated device was exposed to continuous 1 Sun illumination and a constant temperature of 185°F. —Aman Tripathi, Interesting Engineering, 15 Nov. 2025

Another shopper mentioned using one as a magnetic flashlight during car repairs, snapping to metal on the car’s chassis for hands-free illumination right where it’s needed. —Miles Walls, Better Homes & Gardens, 14 Nov. 2025

Word History

Etymology

Middle English illumynacioun, borrowed from Medieval Latin illūminātiōn-, illūminātiō, going back to Latin, "illustriousness," from illūmināre "to give light to, illuminate entry 1" + -tiōn-, -tiō, suffix of verbal action

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for illumination

• abbreviation
• abomination
• acceleration
• accentuation
• accommodation
• accreditation
• acculturation
• accumulation
• acetylation
• adjudication
• administration
• adulteration

Kids Definition

illumination

noun

il·​lu·​mi·​na·​tion il-ˌü-mə-ˈnā-shən 

1

a

: the action of illuminating or state of being illuminated

b

: amount of light

2

: gold or colored decoration in a manuscript

Medical Definition

illumination

noun

il·​lu·​mi·​na·​tion il-ˌü-mə-ˈnā-shən 

1

: the action of supplying or brightening with light or the resulting state

2

: the luminous flux per unit area on an intercepting surface at any given point

called also illuminance

illuminate

il-ˈü-mə-ˌnāt 

transitive verb

illuminated; illuminating