lu·​cid ˈlü-səd How to pronounce lucid (audio)
: suffused with light : luminous
: translucent
snorkeling in the lucid sea
: having full use of one's faculties : sane
: clear to the understanding : intelligible
lucidly adverb
lucidness noun

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Shine a Light on the Origin of Lucid

Lucid comes from the Latin verb lucere, meaning "to shine," which is reflected in its meanings "filled with light" or "shining." It also describes someone whose mind is clear or something with a clear meaning.

Choose the Right Synonym for lucid

clear, perspicuous, lucid mean quickly and easily understood.

clear implies freedom from obscurity, ambiguity, or undue complexity.

clear instructions

perspicuous applies to a style that is simple and elegant as well as clear.

a perspicuous style

lucid suggests a clear logical coherence and evident order of arrangement.

a lucid explanation

Examples of lucid in a Sentence

The stroke also set off a major crisis of presidential succession, as the debilitated and not entirely lucid president continued to cling to office and plan feebly for re-election. Beverly Gage, New York Times Book Review, 13 Dec 2009
His lucid history of this grim subject is scrupulously accurate, so far as I am able to judge … Richard A. Posner, New Republic, 8 Apr 2002
"You would like me to read to you?" "You would oblige me greatly by doing so, Dorothea," said Mr. Casaubon, with a shade more meekness than usual in his polite manner. "I am wakeful: my mind is remarkably lucid." George Eliot, Middlemarch, 1872
The atmosphere, seen through a short space of half or three-quarters of a mile, was perfectly lucid, but at a greater distance all colours were blended into a most beautiful haze … Charles Darwin, The Voyage of the Beagle, 1839
He is able to recognize his wife in his lucid moments. those lucid bands that spread across the arctic sky and are known as the northern lights
Recent Examples on the Web In sharp, lucid prose, Groff explores mystical elements and existential threats, as well as roiling internal conflict. Mia Barzilay Freund, Vogue, 29 Mar. 2024 In a lawsuit filed in March 2023, Matus’ family alleges that Matus was lucid and communicative on the phone with his mother, Lisa, hours before his death. Calmatters, The Mercury News, 28 Mar. 2024 See all Example Sentences for lucid 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'lucid.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin lucidus, from lucēre — see lucent

First Known Use

1591, in the meaning defined at sense 1a

Time Traveler
The first known use of lucid was in 1591


Dictionary Entries Near lucid

Cite this Entry

“Lucid.” Dictionary, Merriam-Webster, Accessed 13 Apr. 2024.

Kids Definition


lu·​cid ˈlü-səd How to pronounce lucid (audio)
: bright with light : luminous
: having full use of one's reasoning ability : clear-minded
: clear to the understanding : plain
lucid writing
lucidness noun

Medical Definition


lu·​cid ˈlü-səd How to pronounce lucid (audio)
: having, showing, or characterized by an ability to think clearly and rationally
lucidity noun
plural lucidities

More from Merriam-Webster on lucid

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