Having one's anus forcefully, repeatedly and not-always-voluntarily resized. Size 9ing is most often performed courtesy of one's new cellmate's johnson, although at some parties, a proper piss-on / pass-out may elicit the act.
Guy 1: "Why is Shiela walking all funny?"
Guy 2: "She got Size 9'ed after passing out face down on the couch at Bob's party."
When a man will search for hours to find something that is laying out in the open on a table. Items are often easily found by a women.
Man: "I have been searching for hours for keys."
Woman: "You mean the ones sitting there on the coffee table?"
Man: "Where?"
Woman: "Right there in the middle of that table."
Man: "oh, must have been Male Pattern Blindness"