A dready fedy is a dealer or a user who has been busted(by the Feds) and has agreed to turn in one or more other dealers in order to minimize their own charges. They can be particularly dangerous because they can appear to be harmless, by having dreadlocks for example. This also refers to UC's who have gone through great lengths to blend in with the crowd, like growing out dreadlocks, and often partake in using drugs themselves in order to gain repore with their victims.
Head #1: "Man, I was blazing with this dread, and he asked me for a kick down, so I gave him a pinky print of molly. The next thing I know he turned around and cuffed me! What the fuck is this world coming to!?"
Head #2: "Dready fedy's bro, dready fedy's."