A funny picture that has three football players, named "Moore", "Goode", and "Dick", who are wearing their jerseys, and are lined up just perfectly, to make it seem like a sentence saying, "Moore Goode Dick" or "More good dick".
Person 1: Dude! I saw that picture on a gay dude's myspace that said moore goode dick! ROFL.
Good Dick Day, or GDD is the uncontrollable size of your dick when you wake up, or when you finish working out, swimming etc. On a good day you have a nice shaft, with an enlarged head, on a bad day you have a shriveled up sleeve of excess skin surrounding a little moles head.