horse slammer Share definition Flag A sexual act where the woman wears a horse mask and neighs during sex and at the end the man cums in the nostrils "I gave my girl such a good horse slammer last night but I missed the nose holes horse slammer by theoghorseslammer September 20, 2017 0 0 Get merch Get the horse slammer mug. Buy Now — $32.95 See more merch