The word "Dab" is a Black (hood) people texting slang. It means "Den A Bitch". We use it while we're texting not physically talking.
"Wyd?"
"Shii nun hungry 'Dab', prolly gon make me sum noodles"
"Make me sum"
"Df I look like makin u sum noodles?? u goofy 'dab' if u think I'm finna make u MY noodles dat I paid for"
"llah Damn, u could've just sed no kinfolk"
"kmsl Nahh yo ass was really dum 'dab' for sayin sum shit like dat bro"