Any person who stops the flow of movement or traffic. Someone who holds other people up in any line, such as in a fast food establisment, movie theater, ect.
I was in food mart yesteray, and i just happened to be in line behind old lady Mc ginty. not only did she use double coupons on every item, which by the way took forty five minutes, she paid for a hundred dollars worth of groceries with pennies! By the time she was done, the line was all the way back at the deli section! What a serious drain clogger!