A non-stop verbal barrage of insults, cursing and racial references. An incoherent rant. A rageful meltdown. Like going postal, except verbally.
"Wow, dude is really letting his ex-girlfriend have it over the phone".
"Yeah, he's going Gibson on her".
Going Gibson is when a person loses their mind with unnecessary anger to the point of absurdity and possible irrational threats and violent acts.
This phrase has been coined due to Mel Gibson's irrational behavior as of late.
The bouncer is Going Gibson on that dude!