sagacious (adj.)

"state or character of being keenly perceptive; acuteness of mental discernment," c. 1500, from French sagacité, from Latin sagacitatem (nominative sagacitas) "keenness of perception, quality of being acute," from sagax (genitive sagacis) "of quick perception, acute," related to sagus "prophetic," sagire "perceive keenly" (from PIE root *sag- "to track down, trace, seek;" source also of Old English secan "to seek;" see seek). Also used 17c.-18c. in reference to animals, with the meaning "acute sense of smell."

"wise, judicious, prudent," c. 1300 (late 12c. as a surname), from Old French sage "wise, knowledgeable, learned; shrewd, skillful" (11c.), from Gallo-Roman *sabius, from Vulgar Latin *sapius, from Latin sapere "have a taste, have good taste, be wise" (from PIE root *sap- "to taste;" see sap (n.1)). Originally of persons, but that use is now poetic only or archaic; of advice, etc., "characterized by wisdom" is from 1530s. Related: Sageness.

word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."