perspicacity

noun

1. (uncountable, usually)Acute discernment or understanding; insight.

   “"I understand," I said. "The fact is that you have the money." His face brightened. He seemed pleased at my perspicacity.”

   “The citizens chose a university. They reasoned, with considerable perspicacity, that taxes come and go in response to political considerations, but a university, once established, is a permanent benefit to a city and a nation.”

   “McEwan certainly has a flair for unusual points of view. Adam, like the baby-in-waiting who narrates Nutshell, is an extraordinarily smart, well-informed, and unorthodox character who catches his supposed caretakers off-guard with his perspicacity.”

2. (uncountable, usually)The human faculty or power to mentally grasp or understand clearly.

   “His very veneration for his father-in-law, combined as it is with a total want of the most ordinary perspicacity, is an additional disqualification.”

   “As the former consists in the transmission of psychic states inappreciable to the normal perspicacity or senses, the transfer cannot pass through the medium of intelligence.”

3. (obsolete, uncountable, usually)Keen eyesight.

   “Attentive consideration of the phenomena of vision has led to the invention of artificial aids by which the sight may be wonderfully strengthened and preserved, and man endowed at once with the perspicacity of the eagle or the minute scrutiny of the insect.”