P.S.- If you do not respond, you will die. HAVE A NICE DAY!

REPLY: Wow, very diametric. I'm not dead. HAPPY NOW?!?!?!
by Kat Bird November 21, 2011
Complete opposites. At opposite ends of the spectrum. Often used with the word opposed.
Her political views are diametrically opposite of his so don't even mention the elections or you will have a fight on your hands.
by thatshit December 17, 2013