fun nazi Share definition Flag A buzzkill, the friend in a group of friends who ruins or atempt to ruin the fun times had by others, intentionally or as a by-product of his/her personallity. Heather, why are you such a fun nazi? fun nazi by james June 9, 2004 0 0 Get merch Get the fun nazi mug. Buy Now — $32.95 See more merch