A jackass attitude, basically meaning an attitude that makes one seem overly rude or obnoxious.
Not to be confused with a "jack-it dude", which is a chronic masturbater.
You: Hey, what's up?
Me: Fuck off.
You: Woah, what's with your jackitude today?
Bob: I heard that Dave is a jack-it dude.
John: Me, too. I heard he masturbates twenty times a day.
Where one of your mates or work collegues has a "Jack Bastard Attitude", or where they act like a jack bastard continuously with the same attitude towards you.
"cor blimey Dave has a bit of a jackitude today."