an equivalent of
dope, awesome, delicious. Usually used for food, a
dish can be "slappin" like it's so good that if someone disputes its awesome godliness they are in for a slappin.
Can also be used in the form of a verb to describe something's slappy
awesomeness.
Yo you should head down to
Dave's food
truck, the pulled pork is slappin
I love eating at that Hawaiian terryaki place,
everything on the menu slaps