of keen and farsighted penetration and judgment; discerning
"However, the new learning from Arab and ancient Greek sources recovered in the twelfth century showed that even the most sagacious ancient authors, including the likes of Ptolemy himself, believed in astrology." James Hannam, The Genesis of Science, 2011
About the Word:
You might expect the root of sagacious to be sage, which means "wise" or "wise man," but actually the two words are not all that closely related. Sagacious traces back to sagire, a Latin verb meaning "to perceive keenly."
It's also related to the Latin adjective sagus ("prophetic"), which is the ancestor of our verb seek. Etymologists believe that sage comes from a different Latin verb, sapere, which means "to taste," "to have good taste," or "to be wise."
Photo: Dan McKay / flickr