1. An irritating person or one who is generally unsuccessful in most regards of life.
2. The word to call someone with whom you are displeased or whom you look down on, especially when you cannot think of another word to fit the situation.
The word was invented by Alexandra Nelson, the defendant on an episode of "Judge Judy."
Judge Judy: "What were you cursing at 5 or 6 of his friends for, you idiot? If there were 5 or 6 of his friends, what were you cursing at them for?"
Alexandra Nelson: "Because they're loserds."