When someone is having trouble
getting laid, they're in a
slump. When you're in a slump, you need an easy score to get your confidence back up and break
the slump - a slumpbuster. Often this means lowering your standards, and sleeping with someone you would never otherwise associate with. The term is obviously negative, and can even damage the reputation of someone who uses it; it implies that the "slumpbuster"'s only purpose is to screw someone who's desperate for sex, and also implies that the person invoking the term uses women for sex. Use with caution; it tends to make things worse for everyone involved.