Another term for erection. Descends from getting boners in school each and every day around 9:30. You can circumambulate along with it down your knee to exhibit every person, you can also tuck it using your ass if you should be embarrassed of it. When your boner is limp and no much longer of price towards sexy ass teacher, its called a "9:31". The perfect time (PM) to possess a large celebration to celebrate the termination of college and beginning of summer time while your mother and father tend to be out-of-town the week-end. Just be sure the beer delivery guy doesn't arrive early and blows your whole plan, understand what I'm sayin'?Made popular by Richard Linklater's 1993 film "Dazed and puzzled".