Uncle Fester Share definition Flag Someone who can't screw in a light bulb. Uncle Fester only knows how to screw herself.... she just sits and festers! You think we are gonna answer your e-mail...well you can just go Uncle Fester!!! Uncle Fester by bobapple October 23, 2005 0 0 Get merch Get the Uncle Fester mug. Buy Now — $32.95 See more merch