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

If the Sun is lower on the horizon, long shadows will stretch across the surface, enhancing relief and revealing depth, ridges, slopes, and crater rims that are often difficult to detect under full illumination. —Richard Tribou, The Orlando Sentinel, 1 Apr. 2026

Tests showed more than 90 percent uniformity in illumination across the target area at a distance of two meters. —Neetika Walter, Interesting Engineering, 31 Mar. 2026

Ralph Lauren Home’s bronze Ollie Lantern with LED illumination takes its hurricane lamp inspiration beyond just its clear glass shade design, emitting a soft candlelight-like glow. —Audrey Lee, Architectural Digest, 31 Mar. 2026

When is peak illumination for Oklahoma City? —Isa Almeida, Oklahoman, 31 Mar. 2026

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