Where you are compulsed by the total arse-kicking-ness of a song (mainly rock and metal) to go ballistic. This can include air guitaring, jumping around, showing the horns and generally making a tit out of yourself. But it's ok, cause you're ROCKING OUT!
* Riff Raff by AC/DC hits *

"ROCK OUT!!!!!"
by Mooman August 28, 2004
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said when an individual has to leave one or more friends abruptly.
"Sorry guys, I got to rock out. My girlfriend just called and told me to come over because her parents just left.
by The Dingo February 18, 2005
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To reach a state of inebriation where one looses track of all time and space. Usually involves mass quantities of beer, one's best friends, and drinking until sunrise.
by Natey G July 9, 2004
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to listen to or play music to such an extent that the mind begins to lose consiousness and a new, more insane alter ego takes control
by yasmin August 3, 2003
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To enjoy music excessively, often while operating a motor vehicle. Rocking out often occurs at a stoplight and can be impulsive. Rocking out often involves playing the air guitar, air drums, and the air tambourine. The alleged rock out star usually plays every instrument in the song at least once. It rarely goes unnoticed.

There have been no reported deaths from rocking out.
Dude, I totally got caught rocking out in my car today.
So? It happens
I was listening to Ace of Base...
Ooooh snap!
by airbag22 October 31, 2006
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Listening to some ill beats on your jam box while headbanging (lightly or heavy) and taping your foot, maybe even signing along.
Dood! You rocking out to a friigin country song!
by Kevin Shaw September 6, 2005
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1. The act of enthusiastically listening to music of the genre rock and roll

2. Public display of crack cocaine
1. I'm gonna go rock out on some ACDC

2. dude yo left yo rock out!
by TomWaxman July 16, 2010
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