sagacious (adj) - having or showing keen perception or sound judgment; discerning, shrewd, or wise [suh-gey-shuhs]
BREAKDOWN: SAG- (seek, trace) + -ACIOUS (full of)
sagacity is the mental quality of being discerning, sound in judgment, and shrewd
“Every man, however wise, needs the advice of some sagacious friend in the affairs of life.” —Plautus