Noun, a form of eroticized rage. Where a person expresses sexual desire through a pattern of harassment and hate directed towards the desired individual.
1. To be so angry that one's blood pressure is so high that there is nearly a sensation of arousal.
2. To intentionally observe something for the purpose of getting pissed off and getting a mad-on, ie, watching the 700 club.
I read the Faith section of the paper today just to get a Mad-on. or I listened to Palin's entire speech. It gave me a raging mad-on.
When someone gets upset on the internet, they are "mad on the internet." This is similar to being mad in real life, but never justifiable, and will always make one look particularly bad or stupid.