perspicuity

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

[…]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.

“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.

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

Transparency; translucence.

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