At a
college or
university, the process of removing
freshmen and other
rookies from a
difficult but
popular major field. Usually, this means
Fs. Lots of them.
Some departments prefer to do the dirty work themselves - stupid required classes that grade on a very steep scale are good for this. Lots, though, prefer to farm out the bloodletting to others - an engineering department might let the physics department take out a good chunk of students, computer science might require a totally useless mathematics course with a high failure rate, etc.