Noun

(-)

(obsolete) Brightness, brilliancy.

*:

*:Thenne sayd he Fair swete fader Ihesu Cryst yf euer I dyd thyng that pleasyd the lord / for thy pyte ne haue me not in despyte for my synnes done afore tyme / and that thou shewe me some thynge of that I seke / And with that he sawe the chamber dore open and there came oute a grete clerenes / that the hows was as bryghte as all torches of the world had ben there

Mental or sensory distinctness; clarity of understanding, perception etc.

*1966 , "The Lowest Depths", Time , 6 September:

*:The daily press is the evil principle of the modern world, and time will only serve to disclose this fact with greater and greater clearness .

The state of being free from obscurities or opacity; distinctness of light, colour etc.

:The clearness of the water meant I could still see the key lying on the river-bed.

The state of being free from obstruction or interference.

:The clearness of the path made for an easy hike.

Noun

Clarity, lucidity, especially in expression; the state or characteristic of being perspicuous.

* 1905 , (George Bernard Shaw), The Irrational Knot , ch. 18,

Whether through the first officer's want of perspicuity or my own stupidity, I was not a bit the wiser for the explanation.

Perspicacity; insight.

*

, title=(The Celebrity), chapter=4 , passage=“Well,” I answered, at first with uncertainty, then with inspiration, “he would do splendidly to lead your cotillon, if you think of having one.” ¶ “So you do not dance, Mr. Crocker?” ¶ I was somewhat set back by her perspicuity .}}

* 1965 , " The Stupid Spy," Time , 19 Mar,

Thompson, a high school dropout, said with rare perspicuity that he doubted the FBI would hire him.

(rare) Transparency; translucence.

* 1900 , (w), The Touchstone , ch. 11,

It must have been on some such day of harsh sunlight, the incisive February brightness that gives perspicuity without warmth.