What is a DUFF? What does Duff stand for? DUFF stands for Desginated ugly fat friend. Do I like this term? No, no I do not. A DUFF doesn't have to be ugly or fat. A DUFF can be someone who doesn't look as good as his/her friends. BEfore you call some one a DUFF. Listen to this: We are all DUFFS. There will always be some one better than you. Someone richer then you. Or more talented. We are all "DUFFS." I am a "DUFF." You are a "DUFF". Your parents are "Duffs". WE ARE ALL "DUFFS". Embrace the fact that you are a "DUFF". You are talented in your own way. You are a "DUFF". I am a DUFF. Even the most popular person at your school is a "DUFF". Guess what, WE ARE ALL DUFFS.