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" acutediscriminatingincisivekeenknifelikepenetratingpenetrativepiercingsharp
painful as if caused by a sharp instrument "a cutting wind"; "keen winds"; "knifelike cold"; "piercing knifelike pains"; "piercing cold"; "piercing criticism"; "a stabbing pain"; "lancinating pain" cuttingkeenknifelikepiercingstabbinglancinatelancinating