classwipe
Any annoying person who- within minutes of a class, conference, or meeting coming to an end- asks an open-ended question which results in an elongated response from the teacher/speaker taking several minutes and goes past the scheduled end time; usually asked by either (a) an ass-kisser, (b) a dumb ass who asked a question already addressed, or (c) by someone whose question only pertains to him/her and no one else in the room.
"We could have been on the road 15 minutes ago, but this classwipe had to ask the professor a question 2 minutes before class ended."