Flat ass Share definition Flag A very flat booty. Usally people with one either hate themselves or think that they don't have one. That girl has such a flat ass! Flat ass by Darkshadowstorm March 29, 2019 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