W.A.S. Share definition Flag Stands for Wide Ass Syndrome. A genetic syndrome that causes the subject to have an enlarged posterior. D! Look! Those chicks have a bad case of W.A.S.!! W.A.S. by Annnonymous January 31, 2007 0 0 Get merch Get the W.A.S. mug. Buy Now — $32.95 See more merch