Source : Webster's Revised Unabridged Dictionary (1913)

Perspicacious \Per`spi*ca"cious\, a. [L. perspicax, -acis, fr.
   perspicere to look through: cf. F. perspicace. See
   {Perspective}.]
   1. Having the power of seeing clearly; quick-sighted; sharp
      of sight.

   2. Fig.: Of acute discernment; keen. --
      {Per`spi*ca"cious*ly}, adv. -- {Per`spi*ca"cious*ness}, n.

Source : WordNet®

perspicaciousness
     n : intelligence manifested by being astute (as in business
         dealings) [syn: {shrewdness}, {astuteness}, {perspicacity}]