It can also refer to an item of clothing or a particular fashion look. It can be used to describe someone who is doing really well at something too.
(for a video game it can also be another way of saying 'Im running with this...' for example for C.O.D it's like saying 'Im running with this class...' Instead you say 'Im rocking the sniper class for this game...' etc.)
-Hey man how are you doing so good?
-I'm rocking the sniper class and the chopper gunner for my killstreak thats how!
To describe someone doing well: (eg. playing rugby in real life)
-Hey i've scored 5 tries so far!
-Wow man you are seriously rocking it today!!
For clothes: (eg. Fashion, outfits etc.)
-Dude you look great for the fancy dress party tonight! That looks awesome!
-Yeah thanks man, I'm rocking the 'Elvis Presley' look tonight!
2. The act of blowing an audience's mind through a musical performance.
3. Being of greatly above average quality.
4. Using crack cocaine.
2. The band was rocking so hard they blew my mind!
3. Hey Stan, when are you gonna make some more of those rocking burgers with the little chunky things in them?
4. He may sleep it off in jail tonight, but he'll be rocking again tomorrow.