Stands for Super Sensational. Expression of utter amazement and admiration of an act or person.
Yo girl, I can't believe you. What you just did was double s. You da bomb.
A variation of smart ass, but reserved for those who are both sarcastic and intelligent at the same time.
Person 1: If I didn't know you better, I'd think that you're being sarcastic.
Person 2: You dingle-berry, I'm ass smart.