Lux Meaning | Definitions & Examples

Lux means “a measure of illumination on a surface” in English and “light” in Latin. It is also sometimes used as an abbreviation for the country of Luxembourg.

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Lux meaning in English

In English, lux is a noun and the unit of measurement for illumination. Lux measures the amount of visible light that falls onto a surface (the light density on a surface). Its plural form is also lux, and its measurement symbol is “lx.”

Lux is important in disciplines that rely on light, like photography, videography, architecture, interior design, engineering, lighting, and technology. For example, device screens often use lux readings to automatically adjust brightness.

Lux is also sometimes used as an abbreviation for “Luxembourg,” particularly when referring to its airport, whose airport code is “LUX.”

Lux meaning in Latin

In Latin, lux means “light.” With this meaning, lux is mostly used in religious, educational, or cultural contexts. Artists have used it in the titles of artworks, films, songs, etc. (e.g., the album Lux by Spanish singer Rosalía), and brands sometimes use lux to suggest luxury, clarity, or refinement (e.g., the Lux bath and body brand from Unilever).

Lux aeterna meaning

Lux aeterna (sometimes written as lux æterna) means “eternal light.” It is a chant sung during the Catholic Mass for the Dead. The chant’s first line—Lux aeterna luceat eis, Domine—means “May eternal light shine upon them, Lord.”

Like lux on its own, lux aeterna is also used as the title of artworks; for example, several orchestral compositions and a 2022 song by metal band Metallica bear this name.

Fiat lux meaning

Fiat lux means “Let there be light.”

This phrase comes from the Book of Genesis in the Judeo-Christian Bible, but it’s also used metaphorically to represent the “light” of knowledge compared to the “darkness” of ignorance. For example, Fiat lux is the motto of the University of California.

Lux name meaning

Lux is also a gender-neutral first name. It carries the connotations of clarity, enlightenment, and hope. It’s related to names like Lucy, Luke, Lucas, Lucía, Lucien, etc., which also mean “light.”

As a surname, Lux is usually French or German and means “son of Lucas” or “lynx” (Luchs in German). A few notable people with this surname are Germán Lux, a former Argentine soccer player, and Gavin Lux, an American baseball player.

Frequently asked questions about lux meaning

What’s the meaning of post tenebras lux?

Post tenebras lux is a Latin phrase meaning “After darkness, light.” Post means “after,” tenebras means “darkness,” and the meaning of lux is “light.”

The phrase was adopted as the motto of the Protestant Reformation, as Protestants believed they had rediscovered spiritual enlightenment after a period of spiritual darkness under the Catholic Church.

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What’s the meaning of lux et veritas?

Lux et veritas is a Latin phrase that means “light and truth.” The meaning of lux is “light.” Et means “and,” and veritas means “truth.”

Lux et veritas is the motto of several educational institutions, most notably Yale University.

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What’s the meaning of crux sacra sit mihi lux?

Crux sacra sit mihi lux is a Latin phrase that means “May the holy cross be my light.” It’s a Christian prayer linked to the Medal of Saint Benedict.

It’s often paired with another phrase: Non draco sit mihi dux (“Let not the dragon be my guide”). These reflect the ideas of good (the holy cross) and evil (the dragon) in Christianity.

To learn more about the meaning of crux sacra sit mihi lux, or the meaning of lux or other specific Latin words, ask QuillBot’s AI Chat.