# lux

> English word · Noun · IPA /lʌks/ · frequency rank #18,878

## Definitions
1. In the International System of Units, the derived unit of illuminance or illumination; one lumen per square metre. Symbol: lx

## Etymology
Borrowed from Latin lūx (“light”), from Proto-Indo-European *lewk- (“white; light; bright”). Cognates include Ancient Greek λευκός (leukós, “white, blank, light, bright, clear”), Ancient Greek λύκη (lúkē, “light, morning twilight”), Sanskrit रोचते (rocate), Middle Persian 𐭩𐭥𐭬 (rōz, “day”) and Old English lēoht (noun) (English light).

## Easily confused with
- **LV** (https://plainspell.com/en/vs/lux-vs-lv)
- **lx** (https://plainspell.com/en/vs/lux-vs-lx)
- **LZ** (https://plainspell.com/en/vs/lux-vs-lz)
- **lyn** (https://plainspell.com/en/vs/lux-vs-lyn)
- **luz** (https://plainspell.com/en/vs/lux-vs-luz)
- **lye** (https://plainspell.com/en/vs/lux-vs-lye)
- **lynx** (https://plainspell.com/en/vs/lux-vs-lynx)
- **luxe** (https://plainspell.com/en/vs/lux-vs-luxe)
- **Luxor** (https://plainspell.com/en/vs/lux-vs-luxor)
- **l** (https://plainspell.com/en/vs/l-vs-lux)
- **LA** (https://plainspell.com/en/vs/la-vs-lux)
- **le** (https://plainspell.com/en/vs/le-vs-lux)
- **li** (https://plainspell.com/en/vs/li-vs-lux)
- **Lt** (https://plainspell.com/en/vs/lt-vs-lux)
- **lo** (https://plainspell.com/en/vs/lo-vs-lux)
- **lb** (https://plainspell.com/en/vs/lb-vs-lux)
- **LP** (https://plainspell.com/en/vs/lp-vs-lux)
- **LN** (https://plainspell.com/en/vs/ln-vs-lux)
- **Ls** (https://plainspell.com/en/vs/ls-vs-lux)
- **lg** (https://plainspell.com/en/vs/lg-vs-lux)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/lux