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.