The chain reaction caused during the last 10-15 seconds of class when someone loudly zips their backpack, this in turn causes everyone around him to look up at the clock and immediately start packing.
Guy 1: Class was taking forever today, I had to resort to the zipper effect.
Guy 2: Works every time.
Guy 2: Works every time.
by mmalone July 13, 2009
Get the zipper effectmug.