cactus ass Share definition Flag A prickly, fiery burning in the rectal cavity during the act of defecation, as though one were passing a cactus through the colon. Remind me not to get the Inferno Burger next time we go out to eat; that gave me mad cactus ass. cactus ass by Dodger of Zion November 19, 2010 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