Nerdmare Share definition Flag A nightmare in which a person, specifically a nerdy person, forgets some of their nerd knowledge, such as a complicated math equation or a video game cheat. Eddy dreamed that he forgot half the elements in the periodic table. What a nerdmare! Nerdmare by xBayD August 2, 2009 0 0 Get merch Get the Nerdmare mug. Buy Now — $32.95 See more merch