Webster's Revised Unabridged Dictionary · 1913

Perspicacious

Perspicacious (pẽr`spi*kā"shus) , adjective

[Latin perspicax, -acis, from perspicere to look through: compare French perspicace. See Perspective.]

1.
Having the power of seeing clearly; quick-sighted; sharp of sight.
2.
Figuratively: Of acute discernment; keen.