When a guy slides down between the bed and the wall to hide from his girlfriend's incoming parent(s). This is most common with Sicilians because they are usually fucking girls they shouldn't be.
Foreigner: "Hey I tell you what, I almost got caught the other night. I had to slide down between the bed and the wall just before her parents came in."
Duder: "Whoa man, you did a sicilian slide? Damn, that's always a close call!"
The technique of sliding between two cars from an adjacent lane during high speed driving with 5 feet of space between the cars. No rearview mirror necessary.
Damn Frank, that asshole missed your front bumper by an inch!
-Yep that's a professional niggerslide.