1. (noun) Any over-the-top fan of anything, but normally used to describe tweens and 40+ year old women who obsess over American Idol contestants.
2. (verb) To act in a manner that would suggest being a fantard.
Derived from "fan" and "retard".
Often simply "tard", especially when used in a compound noun to specify the person whom the fans adore.
The term is mostly used on Vote For The Worst.
1. I found a small group of Cooktards on an online forum praying for David Cook's album to go quadruple platinum.
2. I caught my little sister fantarding over Barack Obama at the rally. She was waving signs, screaming, and generally making a fool of herself.