splap Share definition Flag The sound a penis makes when it slaps someone on the forehead. Grifter splapped Blackrose when he was in Texas, while she was DJing. splap by Candi Apple March 30, 2009 Words you can keep railfan mug chonk mug chud mug based mug 67 mug slime mug mogging mug chopped mug thot mug glazing mug huzz mug yams mug larp mug unc mug cracked mug simp mug baddie mug bop mug lolcow mug