Acronym for Fattest Laziest Ugly Smoking Hairy Drug Abusing Fuck.
Bestowed to any who possess the aforementioned qualities. A person of modest genetic appeal who loves to party, have a good time and is laid back with a dash of apathy and a smidge of complacency.
Also a verb: To Flush, meaning to do the act of the qualities mentioned above
I can't believe you woke up at 2pm and the only thing you accomplished was walking from the bed to the Lazy Boy. You've smoked all my cigarettes and drank all my beer. You're such a Flushdaf. Stop flushing around so much, get up, and get more beer.