Someone who acts like an idiot, is extremly annoying and/or stupid.
Can also be used as an adverb when someone or something is doing an action in a Fungdark way.
Also used in place of the word "Cunt"
for example, think of the stupidest person you know. Multiply by 1000...that's a Fundark. Also likes medeival online role playing games, and fat ugly chicks.