smacker Share definition Flag Slang or Street Name for MDMA (Ectasy). The pill or pills is so potent its like a smacker hits you. smacker by oaktown_finest October 24, 2006 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