Gadannamejahn Share definition Flag The subtle mumbling request to have Jon go down on you.must use Australian accent Jon : "What should we do tonight?"Me : "I don't know yet. *under breath* Gadannamejahn." Gadannamejahn by Ender187 August 14, 2011 0 0 Get merch Get the Gadannamejahn mug. Buy Now — $32.95 See more merch