When a white person accidentily starts saying the "N word" in front of a black person and is forced to either stop mid-sentence or pretend it was another word entirely.
Kevin: "Dude I was about to tell that joke but LaQuishawalked in and I let out a nig-slip!"
Slip on shoes that are a very dark shade of black although these can be sandals if worn with black socksand bedtime slippers if they aren't furry. Usually worn at night when the wearer is in a hurry.