Acerbic

Acerbic: sharp criticism; sarcasm; witty criticism, often funny, but always harsh.  

Acerbic once meant, sour tasting, or bitter.  Over time, the word turned into an adjective attached to “wit”.  When we describe someone with “Acerbic wit”, we are describing someone with a sharp tongue.  If you know someone with acerbic wit, you may be tempted to stay out of their verbal line of fire.

From Latin acer, acris (bitter, pungent, sharp, sour).