butt flagging Share definition Flag A golfing act, where one mate picks up the golf flag and throws it so hard it gets entrenched inside his friends ass hole I cant believe my mom took me to go butt flagging for my birthday. My hole still hurts! butt flagging by Dickfiddler April 8, 2017 0 0 Get merch Get the butt flagging mug. Buy Now — $32.95 See more merch