An erect penis that resembles the hands of a clock at 12:00 P.M. (straight up). If a nooner is exhibited during the late evening hours, it can also be referred to by the term midnighter.
I was sitting at work when Frank sent me that NSFW video. I got a pretty big nooner and couldn't wait to get home and FAP.
by PetefromCrete February 18, 2011