One who is an unending annoyance to others in the worstway at the worst time.
"My little brother managed to volunteer himself as my escort to my girlfriends house. I swear until my mom gets a babysitter he will continue to be a total cock barnacle.
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.