Hot, but mean-spirited, almost violent sex used to punish someone. Sometimes it's used to get back at a significant other. Sometimes it's used to make the significant other wake up with scars, bruises, and/or the inability to walk straight.
Not quite rage, not quite passion, but a whole lot of nasty sex. The kind of sex you give to your partner when something about them pisses you off, but you still want to fuck them anyway.