Slap off. Noun. English. A contest between two people who bear some sort of grudge and attempt to resolve it through the force or impact of a slap to the face.
Imagined slap off: Lauren Bacall vs Elisabeth Hasselbeck -- Winner, Bacall. Slap off in cinema: Terry Ann Wolfmeyer vs Adam 'Shep' Goodman in The Upside of Anger -- Winner, Wolfmeyer.