Incisive

Part of speech: adjective (a.)

1. Having the quality of incising, cutting, or penetrating, as with a sharp instrument; cutting; hence, sharp; acute; sarcastic; biting. "An incisive, high voice." G. Eliot. And her incisive smile accrediting That treason of false witness in my blush. Mrs. Browning.

2. Of or pertaining to the incisors; incisor; as, the incisive bones, the premaxillaries.