Trenchant
[TREN-chənt]
Adjective
Middle English, 13th century
Being sharp, intense, and forceful. Characterized by energy and effectiveness
Trenchant is often used to describe commentary or criticism. If you have a trenchant delivery, you’re known for your biting wit. An obsolete definition of trenchant means physically having a sharp blade. While the adjective is now used in a more figurative sense, a powerful, trenchant remark can still leave wounds.
Example: My trenchant descriptions of U.S. politics alienates some people, but excites others.
Chief Writing Wolf 
That’s a new word! Thanks!
I think I’d heard it once before, many years ago.