A sub-genre of Dubstep. Although it is quite likely it was at one point a real genre, it has had its meaning changed entirely and is used more as an insult within the Dubstep community, or is often used as a word to describe a song which people may not necessarily like. It is usually used among hipsters or fanboys of a certain artist as an insult to every other Dubstep artist.
Skrillex Fan: Why the hell do people listen to Skream? He's just a shitty Brostep artist!
Skream Fan: Why the hell do people listen to Skrillex? He's just a shitty Brostep artist!
Dubstep Fan: Why the hell are these two bitching to eachother? I'm a real Dubstep fan, and personally, I like both Skrillex and Skream!