Etymograph

English

lucidity

Lucidity comes from Late Latin lūciditās ‘lucidity, brightness, radiance’, from Latin lūceō ‘shine’, and ultimately from Proto-Indo-European *lewk- ‘bright’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*lewk-1‘bright’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*lukéh₁yeti1reconstructed
  3. Proto-Italicc. 1500–700 BCE*l(o)ukēō1uncertain
  4. Latinc. 75 BCE–200 CElūceō1‘shine’
  5. Latinc. 75 BCE–200 CElūcidus2‘lucid’
  6. Late Latinc. 200–600 CElūciditās3‘lucidity, brightness, radiance’
  7. Frenchc. 1600–presentlucidité3
  8. Englishearliest quotation 2024lucidity3

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin lucidus
  2. 2 Wiktionary, Latin luciditas
  3. 3 Wiktionary, English lucidity
  4. Earliest quotation in Wiktionary’s entry: 2024, Alex Williams, Morrie Markoff, Listed as Oldest Man in the U.S., Dies at 11: “He was notable not only for his longevity but…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*lewk-Wiktionary, Latin lucidus‘bright’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*lukéh₁yetiWiktionary, Latin lucidusreconstructed
  3. Proto-Italicc. 1500–700 BCE*l(o)ukēōWiktionary, Latin lucidusuncertain
  4. Latinc. 75 BCE–200 CElūceōWiktionary, Latin lucidus‘shine’
  5. Latinc. 75 BCE–200 CElūcidusWiktionary, Latin luciditas‘lucid’
  6. Late Latinc. 200–600 CElūciditāsWiktionary, English lucidity‘lucidity, brightness, radiance’
  7. Frenchc. 1600–presentluciditéWiktionary, English lucidity
  8. Englishearliest quotation 2024lucidityWiktionary, English lucidity. Earliest quotation in Wiktionary’s entry: 2024, Alex Williams, Morrie Markoff, Listed as Oldest Man in the U.S., Dies at 11: “He was notable not only for his longevity but…”

Linked words

through Proto-Indo-European *lewk- ‘bright’

light, low, link, los, ounce, lucy, lea, lunar, luna, illumination, illuminate, luminous, lux, lynx, lumen, lumia, luce, luminosity, loach, lum, luminescent, lune, luminary, leucine, luminal, 73 more

through Latin lūceō ‘shine’

translucent, lucent, 10 more

Today it means

noun The property of being lucid; lucidness.

Sources

Sources: Wiktionary, “lucidity”; the older steps come from the Wiktionary entries for Latin lucidus, Latin luciditas. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *lewk- / lucidity

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