dumdum Share definition Flag A pet name for someone who is stupid Billy: 'what's that?' Jenny: 'That's a cucumber you dumdum' dumdum by a right jammy dodger October 14, 2007 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