C.A.D is an acronym for Computer Aided Death. It is common in engineering courses, for students to be forced, by the evil tutors to sit for hours in C.A.D class, which is analagous to the Nazi death camps. Being forced to endure C.A.D is like having your brain removed from your skull, dropped from the fourth floor onto a concrete courtyard covered in glass, then a 7 foot professional wrestler bodyslamming it, then finally it is placed in a blender and blended on the highest setting with a little salt.
Tutor and torture both come from the same Latin root word, Totor.
C.A.D has often been referred to as Computer Aided Design. This is only by the tutors, as no student can survive the experience.