Cumster Share definition Flag Combination of Cum and Dumpster. A person (usually a woman) that uses her body for men to unload millions of potential children. Dude, Lisa is a real Cumster. She always shows up on circle jerk night. Cumster by Hexx5150 November 23, 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