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

(2)

: decorative lighting or lighting effects

c

: decoration by the art of illuminating

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

• 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

The full moon reaches peak illumination at 4:36 p.m. EDT (2036 GMT) on July 10 and will become visible when itrises over the southeastern horizon as the sun sets in the evening sky. —Anthony Wood, Space.com, 10 July 2025

The Buck Moon will reach peak illumination on July 10 at 4:37 p.m. EST. —Cailey Gleeson, jsonline.com, 9 July 2025

The moon is currently in its waxing crescent phase, at 48% illumination, according to Space.com. —Jenna Prestininzi, Freep.com, 3 July 2025

When is the full moon in June 2025? June's strawberry moon will reach peak illumination on Wednesday, June 11, at 3:44 a.m. ET, according to Space.com. —Haadiza Ogwude, The Enquirer, 2 July 2025

Word History

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