lucid

[loo-sid]
adjective
  1. easily understood; completely intelligible or comprehensible: a lucid explanation.
  2. characterized by clear perception or understanding; rational or sane: a lucid moment in his madness.
  3. shining or bright.
  4. clear; pellucid; transparent.

Origin of lucid

1575–85; < Latin lūcidus, equivalent to lūc-, stem of lūx light1 + -idus -id4
Related formslu·cid·i·ty, lu·cid·ness, nounlu·cid·ly, adverbnon·lu·cid, adjectivenon·lu·cid·ly, adverbnon·lu·cid·ness, nounun·lu·cid, adjectiveun·lu·cid·ly, adverbun·lu·cid·ness, noun

Synonyms for lucid

Antonyms for lucid

1, 4. obscure. 2. irrational. 3. dim.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for unlucid

lucid

adjective
  1. readily understood; clear
  2. shining or glowing
  3. psychiatry of or relating to a period of normality between periods of insane or irresponsible behaviour
Derived Formslucidity or lucidness, nounlucidly, adverb

Word Origin for lucid

C16: from Latin lūcidus full of light, from lūx light
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unlucid

lucid

adj.

1590s, "bright, shining," from Latin lucidus "light, bright, clear," figuratively "perspicuous, lucid, clear," from lucere "to shine," from lux (genitive lucis) "light," from PIE root *leuk- "to shine, be bright" (see light (n.)). Sense of "easy to understand" first recorded 1786. Lucid interval "period of calm or temporary sanity" (1580s) is from Medieval Latin lucida intervalla (plural), which was common in medieval English legal documents (cf. non est compos mentis, sed gaudet lucidis intervallis). Related: Lucidly; lucidness (1640s).

Online Etymology Dictionary, © 2010 Douglas Harper