acute, discriminating, incisive, keen, knifelike, penetrating, penetrative, piercing, sharp -- (having or demonstrating ability to recognize or draw fine distinctions; "an acute observer of politics and politicians"; "incisive comments"; "icy knifelike reasoning"; "as sharp and incisive as the stroke of a fang"; "penetrating insight"; "frequent penetrative observations")
penetrative, penetrating -- (tending to penetrate; having the power of entering or piercing; "a toxic penetrative spray applied to the surface"; "a cold penetrating wind"; "a penetrating odor")