The act of creating a fictional slang term or phrase which is never seriously used by anyone specifically for addition to Urban Dictionary. The word or phrase usually comes into actual use among a few isolated groups after being accepted to Urban Dictionary, which may or may not include the author and his friends.
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.