Being the under dog, going through the struggle. Knowing what it's like to have nothing, to have almost everything you love taken away from you but some how finding a way to defeat all the opposition and surviving the turmoil. I don't think its about being a criminal or being a hard ass. I think it's just about being a fighter but I also think this definition is limited to hip hop.
As 'Pac put it "I'ma thug 'cause I came from the gutter and i'm still here"