A Designated Unattractive Fat Friend, or a Dumb Ugly Fat Fuck- a duff is a girl who is the ugly chick at the party that would be a considerable hook up with a high amount of alcohol ingested. A duff^2 is the girl at the party who is so fugly that no substance in any form can justify a random hook up
Hey chris, michelle just showed up, but she brought 3 fucking duffs, jill, heather, and theresa.
-one bottle of tequila later
Tom - yo bro, heather is bangin
Chris - yea but shes occupied with mike, how does theresa look.
Tom - Fuck that bro, i wouldnt go near her with a ten foot pole, she is clearly a Duff Squared