The complete opposite of expert. An asspert gets paid to do something he or she is absolutely no good at. An asspert never improves despite years of practice. Assperts are generally located in high school guidance departments but can be found pretty much anywhere in the education field. An asspert will never accept responsibility for bad advice and will inevitably blame the victim.
Joe: Mr. Dunderhead, Instead of adding my journalism class, you scheduled me for FOUR study halls and canceled a full year class.
Dunderhead: Well, I don't want you to slack off just because you're a senior!
Joe: Well, Mr. Dunderhead, you're the asspert.