1.
Lucid writing or speech is clear and easy to understand.
...a ~ account of the history of mankind...
His prose as always ~ and compelling.
= clear
ADJ
~ly
Both of them had the ability to present complex matters ~ly.
= clarity
ADV: ADV with v
~ity
His writings were marked by an extraordinary ~ity and elegance of style.
N-UNCOUNT
2.
If someone is ~, they are thinking clearly again after a period of illness or confusion. (FORMAL)
He wasn’t very ~, he didn’t quite know where he was.
ADJ
~ity
The pain had lessened in the night, but so had his ~ity.
N-UNCOUNT