When a woman orgasms because something was so great but no build up or sexual action was needed. Causes for an insta-o could be a hot guy, delicious food, or something just completely awesome.
The excessive amount of "O's" that are in a text message or similar text status update. Generally caused by a sense of boredom and the willingness to convey that to others.
Kim: Hey, what's up?
Carol: Driving back from Las Vegas. The desert is soooo flat. I can't wait to get home. But the truck in front of us is sloooooow.
Kim: Just a few Boredom-O's there. Sounds really exciting....