English
lux
Lux comes from Latin lūx ‘light’, and goes back to Proto-Indo-European *lewk- ‘white’.
- Proto-Indo-Europeanc. 4500–2500 BCE*lewk-‘white’reconstructed
- Proto-Indo-European, derivedc. 4500–2500 BCE*léwksreconstructed
- Proto-Italicc. 1500–700 BCE*louksreconstructed
- Latinc. 75 BCE–200 CElūx‘light’
- Englishearliest quotation 2025lux
attested reconstructed ? uncertain or disputed
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*lewk-‘white’reconstructed
- Proto-Indo-European, derivedc. 4500–2500 BCE*léwksreconstructed
- Proto-Italicc. 1500–700 BCE*louksreconstructed
- Latinc. 75 BCE–200 CElūx‘light’
- Englishearliest quotation 2025lux
Earliest quotation: 2025, Veronique Greenwood, Your Bedroom Probably Isn't Dark Enough: “Some volunteers slept in ambient light of about 100…”
Linked words
through Proto-Indo-European *lewk- ‘white’
light, low, link, los, ounce, lea, lunar, illumination, luna, illuminate, lynx, translucent, luminous, lucid, lumen, luminosity, lucerne, lumia, leucine, luminescent, lucent, luminary, lune, lum, luminal, 73 more
through Proto-Indo-European *léwks
through Latin lūx ‘light’
Today it means
noun In the International System of Units, the derived unit of illuminance or illumination; one lumen per square metre. Symbol: lx
Language periods are conventional ranges, not dates for this word.
Etymograph / Proto-Indo-European *lewk- / lux