the quality of being easily understood, completely intelligible, or comprehensible: She makes her argument with pointed logic and exemplary lucidity.
the ability to see things clearly; rationality; sanity: In a rare moment of lucidity, the senator sided with his political enemies for the good of the country.

Nearby words

  1. lucia di lammermoor,
  2. lucian,
  3. lucianne,
  4. lucid,
  5. lucida,
  6. lucidly,
  7. lucifer,
  8. lucifer match,
  9. luciferase,
  10. luciferin

Sometimes lu·cid·ness.

Related formsnon·lu·cid·i·ty, noun




easily understood; completely intelligible or comprehensible: a lucid explanation.
characterized by clear perception or understanding; rational or sane: a lucid moment in his madness.
shining or bright.
clear; pellucid; transparent.

Origin of lucid

1575–85; < Latin lūcidus, equivalent to lūc-, stem of lūx light1 + -idus -id4

Related forms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for lucidness



readily understood; clear
shining or glowing
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 lucidness
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for lucidness




Clarity, especially mental clarity.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.