Not quite a double date, but not exactly a date either. It's when you invite someone out on a date, and they pull a defensive maneuver and bring a friend along, as a date shield.
Dude, I asked out that hot chick Sally on a date Saturday to cool party. She said yes, because she knew it was a cool scene, but she turned it into a one-and-a-half date, bringing along her BFF Tina to cock block.
A twosome would involve two normal-sized people, so therefore a one-and-a-halfsome would involve a normal-sized person and a person half the size of a normal person, or a midget.
n. software that is no longer sold or supported by the original publisher / developer, often found as free downloads on the internet because it cannot be obtained elsewhere. Not legal, but often seen as morally acceptable because the company that made it is no longer selling the title, nor releasing it as freeware, therefore abandonware is "keeping the gamealive", so to speak.
Doom II is not abandonware because idstill sells it, while The Incredible Machine is not sold, therefore is abandonware.