Grintin'
This refers to anyone who grins and shines their grill at you so bright that you could go blind.
"Why is you be grintin'?"
Grintin'
Grintin' refers to anyone staring at you, possibly smirking, like wtf you staring at!?
Bitch! Why the fuck you grintin'? (You say this while you grint back at them yourself)