Treasure Butt Share definition Flag A person with a flat ass. It is called "treasure butt" because it is hidden, like treasure. I can't fill out these friggin' jeans. DAMN MY TREASURE BUTT!!! Treasure Butt by SneakySocks May 23, 2004 0 0 Get merch Get the Treasure Butt mug. Buy Now — $32.95 See more merch