flabbergaster Share definition Flag This is when you're in the 69 and rip a monstrous fart directly up the nasal passages of your partner. She nearly choked when he delivered a flabbergaster during their first 69. flabbergaster by Disco Misfit October 4, 2006 0 0 Get merch Get the flabbergaster mug. Buy Now — $32.95 See more merch