lucidity vs clearness

lucidity and clearness both are nouns.

Word	Noun	Adjective	Verb	Adverb
lucidity	Yes	No	No	No
clearness	Yes	No	No	No

As nouns, lucidity and clearness are synonyms defined as:

lucidity and clearness: free from obscurity and easy to understand; the comprehensibility of clear expression

Other synonyms of lucidity include clarity, limpidity, lucidness, pellucidity.

lucidity (noun)	clearness (noun)
free from obscurity and easy to understand; the comprehensibility of clear expression	free from obscurity and easy to understand; the comprehensibility of clear expression
a lucid state of mind; not confused	the quality of clear water