# lu vs lux

> English confusable word pair

## The two words

### lu
*noun · IPA /luː/ · frequency rank #12,273*
Archaic form of loo (“card game”).

### lux
*noun · IPA /lʌks/ · frequency rank #18,878*
In the International System of Units, the derived unit of illuminance or illumination; one lumen per square metre. Symbol: lx

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