English
lucid
Lucid comes from Latin lūcidus ‘clear, bright, shining, full of light’, from lūceō ‘shine’, and ultimately from Proto-Indo-European *lewk- ‘bright’.
- Proto-Indo-Europeanc. 4500–2500 BCE*lewk-1‘bright’reconstructed
- Proto-Indo-Europeanc. 4500–2500 BCE*lukéh₁yeti1reconstructed
- Proto-Italicc. 1500–700 BCE*l(o)ukēō1uncertain
- Latinc. 75 BCE–200 CElūceō1‘shine’
- Latinc. 75 BCE–200 CElūcidus1‘clear, bright, shining, full of light’
- Englishearliest quotation 1837lucid1
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, English lucid
- Earliest quotation in Wiktionary’s entry: 1837, Letitia Elizabeth Landon, The Fête: “The atmosphere was unusually clear, as if loath to…”.
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*lewk-Wiktionary, English lucid‘bright’reconstructed
- Proto-Indo-Europeanc. 4500–2500 BCE*lukéh₁yetiWiktionary, English lucidreconstructed
- Proto-Italicc. 1500–700 BCE*l(o)ukēōWiktionary, English luciduncertain
- Latinc. 75 BCE–200 CElūceōWiktionary, English lucid‘shine’
- Latinc. 75 BCE–200 CElūcidusWiktionary, English lucid‘clear, bright, shining, full of light’
- Englishearliest quotation 1837lucidWiktionary, English lucid. Earliest quotation in Wiktionary’s entry: 1837, Letitia Elizabeth Landon, The Fête: “The atmosphere was unusually clear, as if loath to…”
Linked words
through Proto-Indo-European *lewk- ‘bright’
light, low, link, los, ounce, lea, lunar, lucy, luna, illumination, illuminate, lynx, luminous, lux, lumen, luminosity, lumia, loach, lucerne, luce, luminescent, lum, luminary, lune, luminal, leucine, 72 more
through Latin lūceō ‘shine’
Today it means
adj Clear; easily understood.
Sources
Sources: Wiktionary, “lucid”. 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- / lucid