GDBYF Share definition Flag Stands for "get drunk before you flunk". Commonly used in colleges across the country the week before finals. "Hey are you going to the GDBYF party?" "Yeah, but I have to go to the library after..." GDBYF by vegaswedding989 December 7, 2009 0 0 Get merch Get the GDBYF mug. Buy Now — $32.95 See more merch