Short for "Slow Cars in Formation."
1. An annoying situation on a two-lane highway when 19 cars are in line behind one guy that doesn't want to go any faster than 33 miles per hour
2. On a multiple-lane highway, when two or more cars are going the same speed in different lanes and holding up traffic.
I was going to get here ten minutes ago, but I was stuck behind an 8-car scif for like half an hour.