wiz wit Share definition Flag The only way a philly cheesesteak can be ordered. Wiz wit is slang for "with cheese whiz, "wit" onions. This is a must if you are in Philadelphia. "I want a philly cheesteak, wiz wit" wiz wit by theChony April 5, 2006 0 0 Get merch Get the wiz wit mug. Buy Now — $32.95 See more merch