An abbreviation of the word bullshit, wich can also be used quite fittingly as an abbreviation of Britney Spears.
Dude: This channel blows. It's nothing but a load of BS.
Dude2:Look! there she is!
A song, usually of the rap/hip-hop genre, that has been pruned of all foul language and references to sex or drugs.
"I downloaded the clean mix of that song."