lux

See also: Lux, LUX, and Lux.

English

Pronunciation

• IPA^(key): /lʌks/

• Audio (Southern England):

  (file)

• Homophone: lucks
• Rhymes: -ʌks

Etymology 1

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).

Noun

lux (plural lux or luxes or (rare) luces)

1. In the International System of Units, the derived unit of illuminance or illumination; one lumen per square metre. Symbol: lx
   • 2025 December 9, Veronique Greenwood, “Your Bedroom Probably Isn't Dark Enough”, in TIME‎^[1]:

     Some volunteers slept in ambient light of about 100 lux and some in only 3 lux, which is close to total darkness.

   • For quotations using this term, see Citations:lux.

Derived terms

• isolux
• kilolux
• luxmeter
• microlux
• millilux
• sublux

Related terms

• fiat lux

Translations

the derived unit of illuminance

• Bulgarian: лукс (bg) m (luks)
• Chinese:

  Mandarin: 勒克斯 (zh) (lèkèsī)

• Czech: lux (cs) m
• Esperanto: lukso (eo)
• Finnish: luksi (fi)
• French: lux (fr) m
• German: Lux (de) n
• Greek: λουξ (el) n (loux)
• Indonesian: lux
• Italian: lux (it)
• Japanese: ルクス (ja) (rukusu)
• Korean: 럭스 (reokseu)
• Lithuanian: liuksas m
• Malay: lux (ms)
• Polish: luks (pl) m
• Portuguese: lux (pt) m
• Romanian: lux (ro) m
• Russian: люкс (ru) m (ljuks)
• Spanish: lux (es) m
• Swedish: lux (sv) c
• Thai: ลักซ์ (lák)

Etymology 2

Compare French luxer. See luxate.

Verb

lux (third-person singular simple present luxes, present participle luxing, simple past and past participle luxed)

1. (obsolete, transitive) To dislocate; to luxate.
   • 1726, Homer, translated by Alexander Pope, The Odyssey:

     and as I reel'd I fell, / Lux'd the neck-joint—my soul descends to hell.

   • 1835, Alfred Velpeau, Granville Sharp Pattison, New Elements of Operative Surgery:

     the bones are simply luxed without being broken

See also

• luxed up

References

• “lux”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.

Anagrams

• ULX, XUL, LXU, XLU, UXL

Czech

Pronunciation

• IPA^(key): [ˈluks]

Etymology 1

Etymology tree

Proto-Indo-European *lewk-

Proto-Indo-European *-s

Proto-Indo-European *léwks

Proto-Italic *louks

Latin luxbor.

Czech lux

Borrowed from Latin lux.

Noun

lux m inan

1. lux (unit of illuminance or illumination)

Declension

Declension of lux (hard masculine inanimate)

	singular	plural
nominative	lux	luxy
genitive	luxu	luxů
dative	luxu	luxům
accusative	lux	luxy
vocative	luxe	luxy
locative	luxu	luxech
instrumental	luxem	luxy

Etymology 2

Genericized trademark of the Swedish company AB Lux, later renamed to Electrolux.

Noun

lux m inan

1. vacuum cleaner, vacuum

Derived terms

verbs

• luxovat impf

Further reading

• “lux”, in Příruční slovník jazyka českého (in Czech), 1935–1957
• “lux”, in Slovník spisovného jazyka českého (in Czech), 1960–1971, 1989
• “lux”, in Internetová jazyková příručka (in Czech), 2008–2026

Latin

Etymology

Etymology tree

Proto-Indo-European *lewk-

Proto-Indo-European *-s

Proto-Indo-European *léwks

Proto-Italic *louks

Latin lux

From Proto-Italic *louks, from Proto-Indo-European *léwks. Cognates include Ancient Greek λευκός (leukós, “white, blank, light, bright, clear”), Ancient Greek *λύκη (*lúkē, “light, morning twilight”), Sanskrit रोचते (rocate) and Old English lēoht (English light (noun)).

Pronunciation

• (Classical Latin) IPA^(key): [ˈɫuːks]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈluks]

Noun

lūx f (genitive lūcis); third declension

1. light (of the sun, stars etc.)

   Synonym: lūmen

   Antonym: tenebrae

   • c. 347 CE – 420 CE, Hieronymus, Vulgate Genesis.1.3:

     dīxitque Deus fīat lūx et facta est lūx

     And God said: Let there be light. And there was light.

   1. (metonymic) the Sun

      Synonym: sōl

      • c. 45 CE – 96 CE, Statius, Thebais 4.431–432:

        aut ubi fessa iugis, dulcesque altissima somnos lux monet

        • 2004 translation by D. R. Shackleton Bailey

          or when she is weary from the mountains and the sun at his zenith counsels sweet slumber

          (literally, “or when wearied from the mountains, the highest light [of the sun] advises sweet slumber”)

2. daylight, day, moonlight

   Synonym: aurōra

   prīmā lūce ― at daybreak

   ad lūcem ― at dawn

   • 8 CE, Ovidius, Fasti 6.113–116:

     huic aliquis iuvenum dīxisset amantia verba,
     reddēbat tālēs prōtinus illa sonōs:
     ‘haec loca lūcis habent nimis et cum lūce pudōris;
     sī sēcrēta magis dūcis in antra, sequor.’

     If ever some young man spoke to this [nymph] the words of love, immediately she replied with statements such as: “These places have too much of daylight and, with the light, [too much] of shame; if you lead to more secluded caves, I [will] follow [you].”
     (A clever ruse used by Cardea; along the journey to the cave, she would then hide from her unsuspecting suitor.)

3. life

   Synonym: vīta

4. (figuratively) public view
5. glory, encouragement
6. enlightenment, explanation
7. splendour
8. eyesight, the eyes, luminary

Declension

Third-declension noun.

	singular	plural
nominative	lūx	lūcēs
genitive	lūcis	lūcum
dative	lūcī	lūcibus
accusative	lūcem	lūcēs
ablative	lūce lūcī	lūcibus
vocative	lūx	lūcēs

• A locative singular lūcī is attested by Plautus, meaning "by daylight".

Derived terms

• ēlūcus
• lūce (“in the daytime”)
• lūce carentēs (“the dead”)
• lūcidus
• lūcifer
• lūcīnus, Lūcīna
• lūculentus
• prīmā lūce (“at daybreak”)

Related terms

• luceo, lucere
• lūmen

Descendants

Descendants

• Insular Romance:
  • Sardinian: luche, lughe, luxi
• Balkano-Romance:
  • Romanian: luce
• Italo-Dalmatian:
  • Corsican: luce, luci
    • Gallurese: luci
    • Sassarese: luzi
  • Dalmatian: loic
  • Italian: luce
  • Neapolitan: luce
  • Sicilian: luci
  • Venetan: łuxe
• Gallo-Italic:
  • Emilian: lûṡ
  • Ligurian: luxe, lûxe
  • Lombard: lus, lüs
  • Piedmontese: luce, lus
  • Romagnol: luš, luș
• Rhaeto-Romance:
  • Friulian: lûs
  • Romansh: glisch, glüsch, gleisch
• Gallo-Romance:
  • Occitan: lutz
  • Old Catalan: luts
• Ibero-Romance:
  • Aragonese: luz
  • Old Galician-Portuguese: luz
    • Galician: luz
    • Portuguese: luz
  • Old Leonese:
    • Asturian: lluz
    • Extremaduran: lus
    • Leonese: lluz
    • Mirandese: lhuç
  • Old Spanish: luz
    • Ladino: luz / לוז
    • Spanish: luz
• Borrowings (unit of illuminance):
  • → Catalan: lux
  • → Czech: lux
  • → English: lux
  • → Finnish: luksi
  • → French: lux
  • → Greek: λουξ (loux)
  • → Italian: lux
  • → Polish: luks
  • → Portuguese: lux
  • → Spanish: lux
  • → Swedish: lux

References

• “lux”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “lux”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• "lux", in Charles du Fresne du Cange, Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• “lux”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.
• Carl Meißner; Henry William Auden (1894), Latin Phrase-Book‎^[2], London: Macmillan and Co.
  • before daybreak: ante lucem
    
  • the day is already far advanced: multus dies or multa lux est
    
  • to see the light, come into the world: in lucem edi
    
  • those to whom we owe our being: ei, propter quos hanc lucem aspeximus
    
  • to sleep on into the morning: in lucem dormire
    
  • to shun publicity: publico carere, forum ac lucem fugere
    
  • (ambiguous) at daybreak: prima luce
    
  • (ambiguous) in full daylight: luce (luci)
    
  • (ambiguous) to enjoy the privilege of living; to be alive: vita or hac luce frui
    
  • (ambiguous) to shun publicity: forensi luce carere
    
  • (ambiguous) this is as clear as daylight: hoc est luce (sole ipso) clarius
    
• Online Latin dictionary, Olivetti

Portuguese

Etymology

Borrowed from Latin lux. Doublet of the inherited luz.

Pronunciation

• (Brazil) IPA^(key): /ˈluks/

• (Portugal) IPA^(key): /ˈluks/

• Hyphenation: lux

Noun

lux m (plural lux or luxes)

1. lux (the derived unit of illuminance)

Further reading

• “lux”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “lux”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Etymology

Borrowed from French lux.

Noun

lux m (plural lucși)

1. lux

Declension

	singular		plural
	indefinite	definite	indefinite	definite
nominative-accusative	lux	luxul	lucși	lucșii
genitive-dative	lux	luxului	lucși	lucșilor
vocative	luxule		lucșilor

Senhaja de Srair

Alternative forms

• lwaxt-dda (Hmed)

Etymology

Etymology tree

Arabic الوَقْت (al-waqt)

Moroccan Arabic الوقت (el-waqt)bor.

Senhaja de Srair lux

Borrowed from Moroccan Arabic الوقت (el-waqt), from Arabic الوَقْت (al-waqt). Doublet of lweqt.

Pronunciation

• IPA^(key): /luχ/

Adverb

lux (Tifinagh spelling ⵍⵓⵅ) (Hmed, Ketama, Taghzut, Zerqet)

1. now

   Synonyms: daba, derwax (Ketama), amka (Hmed), imi (Taghzut)

References

• Gutova, Evgeniya; Byler, Jonathan (2025), “Senhaja de Srair - English Dictionary”, in Webonary‎^[3], retrieved 2025
• Gutova, Evgeniya (2021) Senhaja Berber Varieties: Phonology, Morphology, and Morphosyntax (Thesis)‎^[4], Paris, France: HAL

Spanish

Etymology

Etymology tree

Proto-Indo-European *lewk-

Proto-Indo-European *-s

Proto-Indo-European *léwks

Proto-Italic *louks

Latin lūxlbor.

Spanish lux

Learned borrowing from Latin lūx. Doublet of the inherited luz.

Pronunciation

• IPA^(key): /ˈluɡs/ [ˈluɣ̞s]
• Rhymes: -uɡs
• Syllabification: lux

Noun

lux m (plural lux)

1. lux

Further reading

• “lux”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025

Swedish

Etymology

Borrowed from Latin lux.

Noun

lux c

1. lux (singular and plural)