SLMH Share definition Flag Slap my head. To take ones hand and pound against ones forehead, as if trying to say "duh" to ones self, or calling yourself an idiot. "I went to Cancun last weekend and should have brought a condom"... SLMH, I'm such an idiot. SLMH by D'oh Guy July 31, 2011 0 0 Get merch Get the SLMH mug. Buy Now — $32.95 See more merch
